Background: Hip fractures are the most severe complication of osteoporosis, yet patients who suffer hip fracture rarely receive adequate treatment. Aim: To assess diagnosis and treatment of osteoporosis in patients with hip fracture. Patients and methods: a retrospective study in 203 patients admitted for hip fracture surgery at two medical institutions in Santiago, Chile. Clinical data from 101 patients from the Hospital Clínico Pontificia Universidad Católica de Chile (a university tertiary care hospital, HCPUC) and 102 patients from Hospital de Urgencia de la Asistencia Pública (a public emergency hospital, HUAP) were reviewed. We also evaluated incidence of new fractures, further treatment of osteoporosis and functionality, by means of a telephonic survey of 48% of patients (n=99) 12.3±5.3 months after hip fracture in HCPUC and 16.5±3.0 months for HUAP. Results: A previous diagnosis of osteoporosis was present in 2.9% and 1% of cases, and treatment prior to fracture in 3.9% and 0% of cases from HCPUC and HUAP, respectively. None of the patients in HUAP were diagnosed with osteoporosis during hospital stay or given treatment for this condition at discharge, in comparison to 0.9% (n=1) and 2% (n=2), respectively, in HCPUC. Seven and six percent of cases presented prior hip fractures. Telephonic follow up of patients revealed that 75.6% persisted without treatment for osteoporosis. At follow up, 2.9% and 3% of patients in HCPUC and HUAP had presented new hip fractures. At the time of survey 30.9% and 34% of patients, respectively, were considered invalid. Conclusions: Missed diagnosis and failure to treat osteoporosis occurred in over 90% of patients admitted for hip fracture, regardless of the different complexities in the hospitals of admission. The data suggest that lack of medical action on these issues may play a role in failure to prevent new hip fractures (Rev Méd Chile 2003; 131: 773-8)