OBJECTIVE: To estimate the hospitalisation costs of accidental fall injuries in the EU resulting from the use of benzodiazepines. METHODS: Risk and exposure data were obtained from the Dutch Pharmo system, a population-based register of drug-dispening records and hospital records. The population attributable risk (PAR) was calculated using the age-specific prevalence estimates of benzodiazepine use and the corresponding relative risk (RR), obtained from a case-control study in community-dwelling inhabitants over 55 years of age in defined areas of The Netherlands covering the period 1985-2000. Annual hospitalisation costs of benzodiazepine-related fall injuries were based on the age-specific PARs and extrapolated to the European population usingaccident and demographic data of the EU. All analyses were performed from the perspective of a third-party payer. RESULTS: Fall injuries in the study population were significantly associated with benzodiazepine use (RR 1.6, 95% CI 1.4-1.7), especially inthose aged over 85 years (RR 3.6, 95% CI 2.9-4.5). The total annual hospital direct medical costs in 2000 of fall-related injuries attributable to benzodiazepine use were Euro 1.8 billion (95% CI Euro 1.5-2.2 billion) in the EU. CONCLUSIONS: The estimated costs of hospitalisations of accidental-fall injuries related to benzodiazepine use in the EU varied between Euro 1.5 and Euro 2.2 billion each year. More than 90% of these costs were in the elderly, with hip fractures as the major contributor. Discontinuing benzodiazepines in the elderly and/or substituting them with other drugs not associated with the risk of falls in the elderly will to a large extent prevent these accidents.