A height balanced tree is a rooted binary tree T in which for every vertex v ∈ V (T ), the difference b T (v) between the heights of the subtrees, rooted at the left and right child of v is at most one. We show that a height-balanced treefor every non-leaf vertex. F h has f (h + 2) − 1 vertices where f (h + 2) denotes the (h + 2)th Fibonacci number. Since f (h) ∼ 2 0.694h , it follows that if F h is a subtree of Q n , then n is at least 0.694(h + 2). We prove that F h is a subtree of the hypercube of dimension approximately 0.75h.