diff --git a/examples/functions.e0 b/examples/functions.e0
new file mode 100644
index 0000000..f1caf58
--- /dev/null
+++ b/examples/functions.e0
@@ -0,0 +1,7 @@
+fn compute() -> int {
+  return 42;
+}
+
+fn main() -> int {
+  return compute();
+}
diff --git a/src/ast/llvm.rs b/src/ast/llvm.rs
index a30387c..cb43ed4 100644
--- a/src/ast/llvm.rs
+++ b/src/ast/llvm.rs
@@ -72,6 +72,13 @@ impl Expr<Type> {
           }
         }
       }
+
+      ExprKind::Call(func, args) => {
+        let func_llvm = func.into_llvm();
+        builder.build_call(func_llvm);
+
+        todo!()
+      }
     }
   }
 }
diff --git a/src/ast/mod.rs b/src/ast/mod.rs
index 15260bd..6e3d69b 100644
--- a/src/ast/mod.rs
+++ b/src/ast/mod.rs
@@ -44,6 +44,7 @@ pub enum ExprKind<T> {
   Int(i64),
   Var(String),
   BinOp(Box<Expr<T>>, Op, Box<Expr<T>>),
+  Call(Box<Expr<T>>, Vec<Expr<T>>),
 }
 
 #[derive(Copy, Clone, Debug)]
diff --git a/src/ast/typed.rs b/src/ast/typed.rs
index fff96ab..9dce3e9 100644
--- a/src/ast/typed.rs
+++ b/src/ast/typed.rs
@@ -210,6 +210,25 @@ fn annotate_expr(ctx: &mut AnnotationContext, expr: &Expr<()>) -> Expr<Type_> {
         ty: output,
       }
     }
+
+    ExprKind::Call(func, args) => {
+      let func = annotate_expr(ctx, func);
+      let mut args_annot = Vec::new();
+      let ret_ty = ctx.type_var();
+
+      for arg in args {
+        let arg_annot = annotate_expr(ctx, arg);
+        args_annot.push(arg_annot);
+      }
+
+      // ctx.constrain();
+      // TODO:
+
+      Expr {
+        kind: ExprKind::Call(Box::new(func), args_annot),
+        ty: ret_ty,
+      }
+    }
   }
 }
 
@@ -328,6 +347,14 @@ fn substitute_in_expr_kind(
       let right = substitute_in_expr(assignments, *right)?;
       ExprKind::BinOp(Box::new(left), op, Box::new(right))
     }
+    ExprKind::Call(func, args) => {
+      let func = substitute_in_expr(assignments, *func)?;
+      let args = args
+        .into_iter()
+        .map(|arg| substitute_in_expr(assignments, arg))
+        .collect::<Result<_>>()?;
+      ExprKind::Call(Box::new(func), args)
+    }
   })
 }
 
diff --git a/src/parser.lalrpop b/src/parser.lalrpop
index 8d43793..74c1877 100644
--- a/src/parser.lalrpop
+++ b/src/parser.lalrpop
@@ -42,6 +42,10 @@ Expr: Expr<()> = {
   #[precedence(level = "0")]
   Ident => Expr { kind: ExprKind::Var(<>), ty: () },
 
+  #[precedence(level = "2")]
+  <expr:Expr> "(" <args:Punct<",", Expr>> ")" =>
+    Expr { kind: ExprKind::Call(Box::new(expr), args), ty: () },
+
   #[precedence(level = "13")]
   #[assoc(side = "none")]
   <left:Expr> <op:CompareOp> <right:Expr> => Expr {
@@ -60,3 +64,17 @@ Type: Type = {
 };
 
 Ident: String = r"([A-Za-z][A-Za-z0-9_]*)|(_[A-Za-z0-9_]+)" => <>.to_string();
+
+Punct<P, T>: Vec<T> = {
+  P => vec![],
+  <first:T> <rest:(P Punct<P, T>)?> => {
+    match rest {
+      Some(rest) => {
+        let (_, mut vec) = rest;
+        vec.insert(0, first);
+        vec
+      }
+      None => vec![first],
+    }
+  },
+};