Background and Purpose: Fall prevention through exercise is an ongoing goal of researchers and clinicians. This study compared the effects of aquatic exercise (AE), land exercise (LE) and no exercise (NE) on fall risk factors. Subjects: Seventy-three women, 60 or older, with osteoporosis (OP). Method: Randomized clinical trial comparing balance, posture, strength, mobility, function, falls, and quality of life. Results: Significant differences (p<0.05) were found for participants’ ratings of global change (AE and LE > NE), tandem balance (AE > LE) and function (LE > AE). Joint pain and falls occurred more often during LE. Discussion and Conclusion: Participants experienced significant global improvement with both AE and LE. Less joint pain, reduced falls and improved balance were found in AE, however LE was more effective in improving functional ability at home. Clinicians should consider the individual’s specific impairments and risk factors when recommending exercise programs on land or in water.