There are contradictory reports regarding the effect of soy protein isolate on bone health in menopause. The main objective of this study was to assess the influence of soy isolate protein intake and resistance exercises on isokinetic muscle strength, endurance, power, and bone health parameters in osteopenic/osteoporotic postmenopausal women. Sixty osteoporotic sedentary women (mean age 54.55 years) were randomly assigned to three groups: soy isolate protein (Group A), soy + exercise group (Group B), and control group (Group C). Group B performed supervised progressive resistance exercises 4 times/week for 12 weeks. Muscle performance was measured by isokinetic dynamometry, and bone health was measured by ultrasound densitometry. Analysis of variance showed significant bone and muscle strength gains (p < .05) both in Group A and B, with the improvements more pronounced in Group B. Significant muscle performance changes, after intervention, were evident and bone strength increases may parallel changes in muscle strength.