To know risk factors and the frequency of osteoporosis (OP) in postmenopausal women. Bone mineral density was measured in lumbar spine of 513 postmenopausal women from a hospital of Guadalajara, Jalisco during 2007-2008. The cutoff points of the associated variables were obtained by ROC curves and odds ratio (OR) by logistic regression. The 25.2% (95%CI 21.44-28.96) of the women was OP. The variables associated with OP and cutoff points were age >60 years, weight