diff --git a/mute-interpreter/src/evaluator.rs b/mute-interpreter/src/evaluator.rs
index ec2a137..5ebb6f5 100644
--- a/mute-interpreter/src/evaluator.rs
+++ b/mute-interpreter/src/evaluator.rs
@@ -258,7 +258,33 @@ pub fn eval_node(env: &Environment, ast_node: Node) -> Result<Node> {
 
             Node::List(list)
         }
-        Node::Filter(mut body) => todo!(),
+        Node::Filter(mut body) => {
+            if body.len() != 2 {
+                todo!();
+            }
+
+            let list = body.pop_front().expect("arg count verified above");
+            let list = match eval_node(env, list)? {
+                Node::List(list) => list,
+                _ => todo!(),
+            };
+
+            let func = match body.pop_front().expect("arg count verified above") {
+                node @ Node::Function(_) => node,
+                _ => todo!(),
+            };
+
+            let mut res = VecDeque::new();
+            for node in list {
+                if let Node::Boolean(true) =
+                    eval_node(env, Node::List(vec![func.clone(), node.clone()].into()))?
+                {
+                    res.push_back(node);
+                }
+            }
+
+            Node::List(res)
+        }
         Node::Reduce(mut body) => todo!(),
         Node::Fold(mut body) => todo!(),
 
@@ -455,6 +481,9 @@ mod test {
     #[case("(pop-back (list 1 2 3))", "(1 2)")]
     #[case("(push-back [1 2 3] 4)", "[1 2 3 4]")]
     #[case("(pop-back [1 2 3 4])", "[1 2 3]")]
+    // Iteration
+    #[case("(map '(1 2 3) (fn* (x) (* x x)))", "(1 4 9)")]
+    #[case("(filter '(1 2 3) (fn* (x) (> x 1)))", "(2 3)")]
     fn test_evaluator(#[case] input: &str, #[case] expected: &str) {
         dbg!(input);