diff --git a/src/variables.rs b/src/variables.rs
index fdf1e84..dfe7bd8 100644
--- a/src/variables.rs
+++ b/src/variables.rs
@@ -12,6 +12,8 @@ use crate::pipelines::get_pipeline;
 use crate::HOST_NAME;
 use colored::*;
 use reqwest::{Method, StatusCode};
+use std::collections::HashSet;
+use std::hash::{Hash, Hasher};
 use std::process;
 use std::thread::sleep;
 use std::time::Duration;
@@ -23,6 +25,37 @@ impl PartialEq for EnvironmentVariable {
     }
 }
 
+impl Eq for EnvironmentVariable {}
+
+impl Hash for EnvironmentVariable {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.name.hash(state);
+        self.service.hash(state);
+    }
+}
+
+impl Hash for EnvironmentVariableServiceType {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        match self {
+            EnvironmentVariableServiceType::All => {
+                state.write_u8(1);
+            }
+            EnvironmentVariableServiceType::Author => {
+                state.write_u8(2);
+            }
+            EnvironmentVariableServiceType::Publish => {
+                state.write_u8(3);
+            }
+            EnvironmentVariableServiceType::Preview => {
+                state.write_u8(4);
+            }
+            EnvironmentVariableServiceType::Invalid => {
+                state.write_u8(5);
+            }
+        }
+    }
+}
+
 // Make pipeline variables comparable - if they have the same name and same service they are the same.
 impl PartialEq for PipelineVariable {
     fn eq(&self, other: &Self) -> bool {
@@ -30,6 +63,34 @@ impl PartialEq for PipelineVariable {
     }
 }
 
+impl Eq for PipelineVariable {}
+
+impl Hash for PipelineVariable {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.name.hash(state);
+        self.service.hash(state);
+    }
+}
+
+impl Hash for PipelineVariableServiceType {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        match self {
+            PipelineVariableServiceType::Build => {
+                state.write_u8(1);
+            }
+            PipelineVariableServiceType::FunctionalTest => {
+                state.write_u8(2);
+            }
+            PipelineVariableServiceType::UiTest => {
+                state.write_u8(3);
+            }
+            PipelineVariableServiceType::Invalid => {
+                state.write_u8(4);
+            }
+        }
+    }
+}
+
 /// Retrieves environment variables for the specified environment.
 ///
 /// # Arguments
@@ -134,6 +195,21 @@ pub async fn set_env_vars_from_file(
 
             println!("{:>4} Environment: {} ({})", "⬛", e.id, env.name);
 
+            // ensure there are no duplicate environment variables
+            let duplicates = find_duplicates(e.variables.clone());
+            if duplicates.len() > 0 {
+                for dv in &duplicates {
+                    eprintln!(
+                        "{:>8} {}  name: '{}' service: {}",
+                        "❌".red(),
+                        "ERROR, duplicate variable definition found, please check your file!".red(),
+                        dv.name,
+                        dv.service
+                    );
+                }
+                process::exit(4);
+            }
+
             // The vector that holds the final variables that will be set or deleted. Will be constructed
             // by comparing the variables that are currently set in Cloud Manager and those in the local
             // YAML config file.
@@ -375,6 +451,21 @@ pub async fn set_pipeline_vars_from_file(
 
             println!("{:>4} Pipeline: {} ({})", "⬛", l.id, pipeline.name);
 
+            // ensure there are no duplicate environment variables
+            let duplicates = find_duplicates(l.variables.clone());
+            if duplicates.len() > 0 {
+                for dv in &duplicates {
+                    eprintln!(
+                        "{:>8} {}  name: '{}' service: {}",
+                        "❌".red(),
+                        "ERROR, duplicate variable definition found, please check your file!".red(),
+                        dv.name,
+                        dv.service
+                    );
+                }
+                process::exit(4);
+            }
+
             // The vector that holds the final variables that will be set or deleted. Will be constructed
             // by comparing the variables that are currently set in Cloud Manager and those in the local
             // YAML config file.
@@ -515,3 +606,16 @@ pub async fn set_pipeline_vars_from_file(
         process::exit(2);
     }
 }
+
+fn find_duplicates<T: Eq + Hash + Clone>(vec: Vec<T>) -> Vec<T> {
+    let mut seen = HashSet::new();
+    let mut duplicates = Vec::new();
+
+    for item in vec {
+        if !seen.insert(item.clone()) {
+            duplicates.push(item);
+        }
+    }
+
+    duplicates
+}