diff --git a/Dockerfile b/Dockerfile
index 348d617..4e60329 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,6 +10,7 @@ ENV LANG="en_US.UTF-8" \
   PORTAINER_URL="" \
   PORTAINER_STACK_NAME="" \
   DOCKER_COMPOSE_FILE="" \
+  ENVIRONMENT_VARIABLES_FILE="" \
   PORTAINER_PRUNE="false" \
   PORTAINER_ENDPOINT="1" \
   HTTPIE_VERIFY_SSL="yes" \
diff --git a/README.md b/README.md
index f372c0d..ed470dc 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,7 @@ This is particularly useful for CI/CD pipelines.
 - `PORTAINER_URL` (string, required): URL to Portainer
 - `PORTAINER_STACK_NAME` (string, required): Stack name
 - `DOCKER_COMPOSE_FILE` (string, required if action=deploy): Path to doker-compose file
+- `ENVIRONMENT_VARIABLES_FILE` (string, optional, only used when action=deploy or action=update): Path to file with environment variables to be used by the stack. See [stack environment variables](#stack-environment-variables) below.
 - `PORTAINER_PRUNE` ("true" or "false", optional): Whether to prune unused containers or not. Defaults to `"false"`.
 - `PORTAINER_ENDPOINT` (int, optional): Which endpoint to use. Defaults to `1`.
 - `HTTPIE_VERIFY_SSL` ("yes" or "no", optional): Whether to verify SSL certificate or not. Defaults to `"yes"`.
@@ -60,6 +61,7 @@ export PORTAINER_PASSWORD="password"
 export PORTAINER_URL="http://portainer.local"
 export PORTAINER_STACK_NAME="mystack"
 export DOCKER_COMPOSE_FILE="/path/to/docker-compose.yml"
+export ENVIRONMENT_VARIABLES_FILE="/path/to/env_vars_file"
 
 ./psu
 ```
@@ -84,6 +86,7 @@ This is more suitable for standalone script usage.
 - `-l` (string, required): URL to Portainer
 - `-n` (string, required): Stack name
 - `-c` (string, required if action=deploy): Path to doker-compose file
+- `-g` (string, optional, only used when action=deploy or action=update): Path to file with environment variables to be used by the stack. See [stack environment variables](#stack-environment-variables) below.
 - `-r` ("true" or "false", optional): Whether to prune unused containers or not. Defaults to `"false"`.
 - `-e` (int, optional): Which endpoint to use. Defaults to `1`.
 - `-s` ("yes" or "no", optional): Whether to verify SSL certificate or not. Defaults to `"yes"`.
@@ -94,13 +97,26 @@ This is more suitable for standalone script usage.
 #### Examples
 
 ```bash
-./psu -a deploy -u admin -p password -l http://portainer.local -n mystack -c /path/to/docker-compose.yml
+./psu -a deploy -u admin -p password -l http://portainer.local -n mystack -c /path/to/docker-compose.yml -g /path/to/env_vars_file
 ```
 
 ```bash
 ./psu -a undeploy -u admin -p password -l http://portainer.local -n mystack
 ```
 
+### Stack environment variables
+
+There can be set environment variables for each stack, be it a new deployment or an update. For example:
+
+```bash
+touch .env
+echo "MYSQL_ROOT_PASSWORD=agoodpassword" >> .env
+echo "ALLOWED_HOSTS=*" >> .env
+./psu -a deploy -u admin -p password -l http://portainer.local -n django-stack -c /path/to/docker-compose.yml -g env_vars
+```
+
+Stack environment variables can be enabled through [ENVIRONMENT_VARIABLES_FILE envvar](#with-envvars) or [-g flag](#with-flags).
+
 ### Verbose mode
 
 In verbose mode the script prints execution steps.
diff --git a/psu b/psu
index c68fd7d..021f402 100755
--- a/psu
+++ b/psu
@@ -66,26 +66,27 @@ main() {
   exit 1
 }
 
-##########################
-# Set globals            #
-# Globals:               #
-#   ACTION               #
-#   PORTAINER_USER       #
-#   PORTAINER_PASSWORD   #
-#   PORTAINER_URL        #
-#   PORTAINER_STACK_NAME #
-#   DOCKER_COMPOSE_FILE  #
-#   PORTAINER_ENDPOINT   #
-#   PORTAINER_PRUNE      #
-#   HTTPIE_VERIFY_SSL    #
-#   VERBOSE_MODE         #
-#   DEBUG_MODE           #
-#   STRICT_MODE          #
-# Arguments:             #
-#   None                 #
-# Returns:               #
-#   None                 #
-##########################
+################################
+# Set globals                  #
+# Globals:                     #
+#   ACTION                     #
+#   PORTAINER_USER             #
+#   PORTAINER_PASSWORD         #
+#   PORTAINER_URL              #
+#   PORTAINER_STACK_NAME       #
+#   DOCKER_COMPOSE_FILE        #
+#   ENVIRONMENT_VARIABLES_FILE #
+#   PORTAINER_ENDPOINT         #
+#   PORTAINER_PRUNE            #
+#   HTTPIE_VERIFY_SSL          #
+#   VERBOSE_MODE               #
+#   DEBUG_MODE                 #
+#   STRICT_MODE                #
+# Arguments:                   #
+#   None                       #
+# Returns:                     #
+#   None                       #
+################################
 set_globals() {
   # Set arguments through envvars
   ACTION=${ACTION}
@@ -94,6 +95,7 @@ set_globals() {
   PORTAINER_URL=${PORTAINER_URL}
   PORTAINER_STACK_NAME=${PORTAINER_STACK_NAME}
   DOCKER_COMPOSE_FILE=${DOCKER_COMPOSE_FILE}
+  ENVIRONMENT_VARIABLES_FILE=${ENVIRONMENT_VARIABLES_FILE}
   PORTAINER_ENDPOINT=${PORTAINER_ENDPOINT:-"1"}
   PORTAINER_PRUNE=${PORTAINER_PRUNE:-"false"}
   HTTPIE_VERIFY_SSL=${HTTPIE_VERIFY_SSL:-"yes"}
@@ -102,7 +104,7 @@ set_globals() {
   STRICT_MODE=${STRICT_MODE:-"false"}
 
   # Set arguments through flags (overwrite envvars)
-  while getopts a:u:p:l:n:c:e:rsvdt option; do
+  while getopts a:u:p:l:n:c:e:g:rsvdt option; do
     case "${option}" in
       a) ACTION=${OPTARG} ;;
       u) PORTAINER_USER=${OPTARG} ;;
@@ -111,6 +113,7 @@ set_globals() {
       n) PORTAINER_STACK_NAME=${OPTARG} ;;
       c) DOCKER_COMPOSE_FILE=${OPTARG} ;;
       e) PORTAINER_ENDPOINT=${OPTARG} ;;
+      g) ENVIRONMENT_VARIABLES_FILE=${OPTARG} ;;
       r) PORTAINER_PRUNE="true" ;;
       s) HTTPIE_VERIFY_SSL="no" ;;
       v) VERBOSE_MODE="true" ;;
@@ -130,6 +133,7 @@ set_globals() {
   echo_debug "PORTAINER_URL -> $PORTAINER_URL"
   echo_debug "PORTAINER_STACK_NAME -> $PORTAINER_STACK_NAME"
   echo_debug "DOCKER_COMPOSE_FILE -> $DOCKER_COMPOSE_FILE"
+  echo_debug "ENVIRONMENT_VARIABLES_FILE -> $ENVIRONMENT_VARIABLES_FILE"
   echo_debug "PORTAINER_ENDPOINT -> $PORTAINER_ENDPOINT"
   echo_debug "PORTAINER_PRUNE -> $PORTAINER_PRUNE"
   echo_debug "HTTPIE_VERIFY_SSL -> $HTTPIE_VERIFY_SSL"
@@ -145,6 +149,10 @@ set_globals() {
   check_argument "$PORTAINER_STACK_NAME" "portainer stack name" "PORTAINER_STACK_NAME" "n"
   if [ $ACTION == "deploy" ]; then
     check_argument "$DOCKER_COMPOSE_FILE" "docker compose file" "DOCKER_COMPOSE_FILE" "c"
+    if [ -n "$ENVIRONMENT_VARIABLES_FILE" ] && [[ ! -f "$ENVIRONMENT_VARIABLES_FILE" ]]; then
+      echo_error "Error: File path \"$ENVIRONMENT_VARIABLES_FILE\" not found for \"ENVIRONMENT_VARIABLES_FILE\" environment variable or the \"-g\" flag."
+      exit 1
+    fi
   fi
 }
 
@@ -254,21 +262,22 @@ echo_debug() {
   fi
 }
 
-##########################
-# Create/update a stack  #
-# Globals:               #
-#   STACK                #
-#   DOCKER_COMPOSE_FILE  #
-#   PORTAINER_STACK_NAME #
-#   PORTAINER_URL        #
-#   HTTPIE_VERIFY_SSL    #
-#   PORTAINER_ENDPOINT   #
-#   AUTH_TOKEN           #
-# Arguments:             #
-#   None                 #
-# Returns:               #
-#   None                 #
-##########################
+################################
+# Create/update a stack        #
+# Globals:                     #
+#   STACK                      #
+#   DOCKER_COMPOSE_FILE        #
+#   PORTAINER_STACK_NAME       #
+#   PORTAINER_URL              #
+#   ENVIRONMENT_VARIABLES_FILE #
+#   HTTPIE_VERIFY_SSL          #
+#   PORTAINER_ENDPOINT         #
+#   AUTH_TOKEN                 #
+# Arguments:                   #
+#   None                       #
+# Returns:                     #
+#   None                       #
+################################
 deploy() {
   # Read docker-compose file content
   local docker_compose_file_content
@@ -304,14 +313,19 @@ deploy() {
     local swarm_id
     swarm_id=$(echo $docker_info | jq -r ".Swarm.Cluster.ID // empty")
     echo_debug "Swarm ID -> $swarm_id"
-    
+
     # If there is no swarm ID
     if [ -z "$swarm_id" ];then
       echo_verbose "Swarm cluster not found."
 
       echo_verbose "Preparing stack JSON..."
+      local stack_envvars
+      stack_envvars="[]"
+      if [ -n "$ENVIRONMENT_VARIABLES_FILE" ]; then
+        stack_envvars=$(env_file_to_json)
+      fi
       local data_prefix="{\"Name\":\"$PORTAINER_STACK_NAME\",\"StackFileContent\":\""
-      local data_suffix="\"}"
+      local data_suffix="\",\"Env\":"$stack_envvars"}"
       echo "$data_prefix$docker_compose_file_content$data_suffix" > json.tmp
       echo_debug "Stack JSON -> $(echo $data_prefix$docker_compose_file_content$data_suffix | jq -C .)"
 
@@ -335,8 +349,13 @@ deploy() {
       echo_verbose "Swarm cluster found."
 
       echo_verbose "Preparing stack JSON..."
+      local stack_envvars
+      stack_envvars="[]"
+      if [ -n "$ENVIRONMENT_VARIABLES_FILE" ]; then
+        stack_envvars=$(env_file_to_json)
+      fi
       local data_prefix="{\"Name\":\"$PORTAINER_STACK_NAME\",\"SwarmID\":\"$swarm_id\",\"StackFileContent\":\""
-      local data_suffix="\"}"
+      local data_suffix="\",\"Env\":"$stack_envvars"}"
       echo "$data_prefix$docker_compose_file_content$data_suffix" > json.tmp
       echo_debug "Stack JSON -> $(echo $data_prefix$docker_compose_file_content$data_suffix | jq -C .)"
 
@@ -370,12 +389,17 @@ deploy() {
     local stack_id
     stack_id="$(echo "$STACK" | jq -j ".Id")"
     local stack_envvars
-    stack_envvars="$(echo -n "$STACK"| jq ".Env" -jc)"
+    stack_envvars="$(echo -n "$STACK" | jq ".Env" -jc)"
+    if [ -n "$ENVIRONMENT_VARIABLES_FILE" ]; then
+      local new_stack_envvars
+      new_stack_envvars=$(env_file_to_json)
+      stack_envvars="$(echo -n "${new_stack_envvars}${stack_envvars}" | jq -sjc 'add | unique_by(.name)')"
+    fi
     local data_prefix="{\"Id\":\"$stack_id\",\"StackFileContent\":\""
     local data_suffix="\",\"Env\":"$stack_envvars",\"Prune\":$PORTAINER_PRUNE}"
     echo "$data_prefix$docker_compose_file_content$data_suffix" > json.tmp
     echo_debug "Stack JSON -> $(echo $data_prefix$docker_compose_file_content$data_suffix | jq -C .)"
-    
+
     # Update stack
     echo_verbose "Updating stack $PORTAINER_STACK_NAME..."
     local update
@@ -390,7 +414,7 @@ deploy() {
       @json.tmp)
     check_for_errors $? "$update"
     echo_debug "Update action response -> $(echo $update | jq -C .)"
-    
+
     rm json.tmp
   fi
 }
@@ -436,4 +460,17 @@ undeploy() {
   echo_debug "Delete action response -> $(echo $delete | jq -C .)"
 }
 
+###################################################
+# Convert environment variables from file to JSON #
+# Globals:                                        #
+#   ENVIRONMENT_VARIABLES_FILE                    #
+# Arguments:                                      #
+#   None                                          #
+# Returns:                                        #
+#   JSON string                                   #
+###################################################
+env_file_to_json() {
+  echo "$(env -i $(cat $ENVIRONMENT_VARIABLES_FILE) jq -n 'env | to_entries | map({name: .key, value: .value})')"
+}
+
 main "$@"