We treated 42 postmenopausal women with decreased bone mass for 12 weeks with human growth hormone, growth hormone releasing hormone, or placebo. Bone density and biochemical markers were determined before and during treatment, and 4 weeks after withdrawal. Biochemical markers of bone formation and resorption increased significantly in the group treated with growth hormone, whereas no changes were seen in the other groups. After withdrawal of therapy the bone markers declined without reaching baseline values. Bone density in the forearm, spine and proximal femur was unchanged in all groups. We conclude that treatment with growth hormone stimulates bone metabolism in elderly postmenopausal women with decreased bone mass.