OBJECTIVES: Osteoporosis (OP) and its fragility fractures (FF) impose a large burden on health system and the impact is growing due to population ageing. Severe or established OP defines a T-score < -2.5 in presence of a fragility fracture. We aimed to estimate the prevalence of severe OP in daily consultation of rheumatology and endocrinology services in hospitals of IMSS and ISSSTE and to assess the costs and quality of life (QoL) associated with FF in Mexico. METHODS: A prospective study was performed in 11 specialty (6 rheumatology and 5 endocrinology) services from 9 hospitals of IMSS and ISSSTE through March 1 to April 27, 2010. Data of adults attending to outpatient consultation was collected in a clinical report form. The analysis was done following a frequentist statistical approach. We also conducted a systematic review of published and non-published data of direct medical costs (acute attention, physical therapy and outpatient visits) and QoL related with major FF in Mexico. Expert opinion was used when local information was not available. All costs were updated to December 2010 and figures are expressed in Mexican pesos. RESULTS: During the period of study, 84 out of the 3527 medical consultations were given to patients diagnosed with severe OP, comprising a 2.4% of the total consultations in these services. Prevalence of severe OP was slightly higher in rheumatology (2.6%) than in endocrinology (2.2%) services. First-year total cost per patient with hip, vertebral, forearm and humerus FF were estimated at $82631, $53332, $39006 and $41942, respectively. FF significantly reduced QoL, with hip and vertebral fractures affecting the most. CONCLUSIONS: This study shows that severe OP is common in rheumatology and endocrinology services. Since a prior fracture increases the risk of future fractures, patients with severe OP entail a high economic burden to the health system.