Hip fracture may cause and/or complicate institutionalization. We undertook this study to define its overall prevalence among the residents of four nursing homes in Central Italy as well as its latency and impact on mobility when it occurred within institutions. We also performed a case control analysis with the aim of identifying potential risk factors for hip fracture in nursing home. Among the 211 residents (160 women, mean age 82.2 +/- 9.29 years, and 51 men, mean age 77.1 +/- 8.9 years), 42 were hip fracture cases, with a prevalence of almost 20%, and a female/male ratio of 6/1.23 fractures preceded institutionalization; of these 19 (17 females and 2 males) occurred within the nursing homes (mean age 83.2 +/- 6.3 years). The average interval between institutionalization and fracture was 74.2 months. The impact of hip fracture on mobility was relevant. The percentage of residents ambulating autonomously fell from 95% to 32% among those who had fractured. Fractured subjects were characterized by worse mobility and function than unfractured subjects, while comorbidity, cognitive functions, and use of psychotropic drugs were similar. Prefracture mobility of fractured subjects was better than that of age-and sex-matched residents who had never fractured their hip. Regarding hip fracture in our nursing home population we can conclude that (1) hip fracture is one of the main causes of institutionalization; (2) in most cases hip fracture occurred late in the course of the nursing home stay; (3) the functional impact of the fracture was relevant when it occurred in institutions. We also suggest that preserved mobility may represent an additional risk factor for hip fracture in nursing homes.