40 premenopausic female patients under 45 with established diagnosis of rheumatoid athritis according to the criteria of the american college of rheumatology were studied. they were all under treatment with steroids with an equipment of osteal densitometry by ultrasound of the calcaneus. on analyzing the t-score average (as osteoporosis marker), we found that the lowest value was - 4.5 and the maximum -1.5. the t-student statistical test was used to compare the t-score average according to: dose, time of treament with steroids and time of evolution of the disease. osteoporosis was detected in 23 patients that received more than 20 mg of steroids, in 27 with more than 5 years of treatment with steroids, and in 23 with more than 5 years of evolution of the disease. on exploring the antecedent of fracture and relate it to the time of treatment and to the dose of steroids we observed that 9 patients (81-8 %) with more than 5 years of treatment and 6 (54.5 %) with more than 20 mg of steroids had had fractures.