diff --git a/javascript/AddTwoNumbers.js b/javascript/AddTwoNumbers.js
new file mode 100644
index 0000000..2068a40
--- /dev/null
+++ b/javascript/AddTwoNumbers.js
@@ -0,0 +1,39 @@
+// https://leetcode.com/problems/add-two-numbers/
+// T: O(max(|l1|, |l2|))
+// S: O(max(|l1|, |l2|))
+
+const addTwoNumbers = (l1, l2) => {
+  let p1 = l1;
+  let p2 = l2;
+  let carry = 0;
+  let result_node = new ListNode(-1);
+  let pointer = result_node;
+  while (p1 || p2 || carry !== 0) {
+    let sum = 0;
+    if (p1 !== null && p2 !== null) {
+      sum = p1.val + p2.val;
+      p1 = p1.next;
+      p2 = p2.next;
+    } else if (p1 !== null) {
+      sum = p1.val;
+      p1 = p1.next;
+    } else if (p2 !== null) {
+      sum = p2.val;
+      p2 = p2.next;
+    }
+
+    if (carry !== 0) {
+      sum = sum + carry;
+      carry = 0;
+    }
+
+    if (sum > 9) {
+      carry = Math.floor(sum / 10);
+      sum = sum % 10;
+    }
+
+    pointer.next = new ListNode(sum);
+    pointer = pointer.next;
+  }
+  return result_node.next;
+};