Twenty-one of 46 postmenopausal women were assigned to a home-based exercise program consisting of 60 min of exercise, 3 d/wk. The 25 nonexercisers continued usual daily activities. Each woman had at least one prevalent vertebral fracture and suffered from osteoporosis as defined by the application of WHO criteria to lumbar spine bone mineral density. Vertebral heights were measured using bone densitometry at baseline and 12 mo later. Vertebrae T9 to L4 were all identified for each of the 46 subjects in both the baseline and end-of-study lateral scans. The change in mean vertebral height over the course of the study was -0.3 mm anteriorly, -0.7 mm at the mid-location, and -0.4 mm posteriorly for the nonexercisers. For the exercisers, the corresponding changes were +0.1 mm anteriorly, -0.3 mm at the mid-location, and +0.2 mm posteriorly. The benefit of exercise in preserving vertebral morphometry in patients with osteoporosis deserves further investigation.