Osteoporosis is a disease characterized by a decrease in bone mass. The objective of our study is to test the effect of androgen, estrogen and combined androgen and estrogen as preventive and therapeutic on osteoporosis induced experimentally in female rats by ovariectomy and in male rats by orchidectomy. Samples were collected for determination of serum alkaline phosphatase and urinary calcium. The tibia was separated for bone histomorphometry. Hormonal treatment with testosterone is effective in prevention and treatment of male osteoporosis (best as preventive); while estrogen is equally as preventive as therapeutic in female osteoporosis. Combined therapy with testosterone and estrogen is more effective in treatment of osteoporosis of both male and female rats than in its prevention.