The aim of the present study was to determine whether a 12 week hydraulic resistance circuit training program, could maintain whole body bone mineral density in postmenopausal women. Participants included ten apparently healthy, postmenopausal women (56.5 + 7.5 years) who were allocated into two groups: exercise (EX) and control (CON). EX subjects participated in hydraulic resistance circuit training three days a week for 30 minutes per day. Exercise stations consisted of nine hydraulic resistance machines that targeted the main muscle groups and nine aerobic stations that consisted of dancing, jogging and cycling. Bone mineral density of the whole body was assessed at baseline and 12 weeks in both groups. No significant differences (P< 0.05) in whole body bone mineral density were found between groups determined by repeated measures ANCOVA. However, a trend (P= 0.054) for the EX group to increase whole body bone mineral density (baseline BMD= 1.08 + .07 g/cm2, 12-week= 1.11 + .07) over 12 weeks existed. These results suggest that hydraulic resistance strength training is a safe form of exercise and may be beneficial for maintaining bone mineral density in postmenopausal women. However, further research with a larger population and longer study duration is warranted.