Abstract: A foldable ladder including a foldable support frame mechanism and a head step assembly releasably mounted to the support frame mechanism. The head step assembly comprises a pair of base plates each having protuberances on both sides thereof and a number of step plates each having holes complementary in shape to the protuberances on the base plate. Two step plates and one base plate can be stacked together side by side through protuberance and hole engagement to form a bundle which can be stored within the support frame mechanism in its folded position.