To evaluate the tolerance and effectiveness of conjugated Estrogen for women with established post-menopausal Osteoporosis and hot flushes, with the use of paired comparison, randomized, we tested during an 10 month period the bone mineral contents and plasma glucose in subjects who afforded by premarin in dosages of 0.625 mg for days 1 to 25 and oral medroxy progesterone acetate for days 15 to 25 of a 29 days cycle. All subjects received supplementation to ensure a minimum of 800 mg calcium per day. 25 subjects completed at least 10 month follow up serum calcium, phosphate, glucose and urinary calcium and phosphatae measurements by colorimetric, method. We compared women with herselves, the median change in biochemical studies showed significant decrease in serum calcium, phosphate an urinary excrition of calcium, but significant increase in urinary excrition of phosphate. Fasting plasma glucose did not change significantly. Decrease serum calcium (9.6 compared with 9.16; P<0.005) decrease, serum phosphate (3.77 compared with 3.39; P<0.005), decrease uri calcium (149.81 compared with 121.46, P<0.005), increase uri phosphate (625.83 compared with 676, P<0.005), FBS (92.03 compared with 91.45, 0.1>P>0.05). Regarding the effects of conjugated Estrogen on plasma and urinary calcium and phosphate levels and amelioration of clinical symptoms, we concluded that conjugated Estrogen treatment in effective in post-menopausal Osteoporosis, but we did not find relation between exogenous Estrogen in post-menopausal women with FBS and hot flush