BACKGROUND: Osteoporosis is a common illness frequently leading to serious adverse outcomes for patients. Hip, wrist and vertebral fractures have a considerable impact on both costs to healthcare system and lives of those who suffer from those events. Each year in the US, an estimated 1.5 million fractures occur due to osteoporosis [Riggs and Melton, 1995]. Estimated incremental cost of osteoporosis related events in the subsequent years after fracture is US$4007 [Rousculp, 2007]. Bisphosphonates are widely used and are considered an effective intervention for risk reduction of postmenopausal fractures. The 100% out-of-pocket purchase of medicines by patients is a reality in Brazil. So, a study under patient perspective is an important tool to help decision-making. OBJECTIVES: The present study was conducted to compare the cost of bisphosphonates used for risk reduction of post-menopause vertebral and non-vertebral fractures under patient perspective in Brazil. METHODS: The most important bisphosphonates in the Brazilian market to patients are ibandronate (oral and IV), zolendronate, alendronate and risendronate. There are no head-to-head clinical trials comparing all the compounds. Studies of ibandronate [Eisman, 2008] and zolendronate [McClung, 2007] demonstrated their non-inferiority against oral bisphosphonates. Therefore, a cost-minimization approach was taken. Drug consumer prices were obtained from official public sources [Kairos magazine, May 2009]. Since the time horizon of this analysis is one-year, no discount rate was utilized. Costs are presented in Brazilian Reais (US$1.00 ~ R$2.00 in May 2009). RESULTS: Total cost per patient was R$1534.36 for IV ibandronate, R$1685.83 for alendronate,  R$1941.17 for oral ibandronate, R$1951,26 for zolendronate and R$2354.52 for risendronate . CONCLUSIONS: Findings suggest that IV ibandronate is a cost-saving therapy with potential of reducing the total treatment cost per patient from 9% up to 35%, when compared to alendronate and risendronate respectively, considering patient perspective in Brazil.