diff --git a/ruby/167-Two-Sum-II.rb b/ruby/167-Two-Sum-II.rb
new file mode 100644
index 000000000..70573005c
--- /dev/null
+++ b/ruby/167-Two-Sum-II.rb
@@ -0,0 +1,15 @@
+def two_sum(numbers, target)
+  idx_start = 0
+  idx_end = numbers.length - 1
+  while idx_start < idx_end
+    case numbers[idx_start] + numbers[idx_end] <=> target
+    when 1
+      idx_end -= 1
+    when 0
+      return [idx_start + 1, idx_end + 1]
+    when -1
+      idx_start += 1
+    end
+  end
+  nil
+end