Insomnia is a significant problem that may jeopardize elderly residents’ quality of life in long-term care settings. However, there are only a few studies dealing with sleeping disturbances among nursing home residents. The goal of this study was to determine the prevalence of insomnia and its associated factors in nursing home residents. A cross-sectional study ( n = 2332) was conducted among seniors living in long-term care facilities. The findings indicate that 144 (6.2%) participants had an insomnia disorder according to DSM-IV criteria, 17% displayed at least one symptom of insomnia, and more that half of the subjects were benzodiazepine users. According to multivariate analysis, psychological distress (adjusted odds ratio = 1.51) and disruptive behaviors (adjusted odds ratio = 2.10) were the only factors associated with an insomnia disorder among this population. In conclusion, insomnia is a fairly important problem, as a symptom or a syndrome, among elderly people and deserves attention from caregivers. Alternative interventions to benzodiazepine drugs, which are suited to long-term care residents while tailored to these specific care settings, should be developed.