People with dementia are at increased risk of falling. The purpose of this study was to identify predisposing risk factors for falls in older people with and without a diagnose of dementia living in residential care facilities, and to compare the results. Eighty-three residents without dementia (mean age+/-S.D.; 83.5+/-7.1 years) and 103 with dementia (83.6+/-6.3 years) in Umeå, Sweden, participated. The baseline assessment included probable risk factors like walking ability, diagnoses and treatment with drugs. The follow-up period was 6 months. In people with dementia, the fall rate was higher (crude incidence rate ratio 2.55, 95% CI 1.60-4.08) and a larger proportion experienced falls (62% versus 41%). In the group without dementia 54.8% of the variation in falls was explained by a model including orthostatism, "women walking with aid", and treatment with Angiotensin Converting Enzyme (ACE) inhibitors. In the group with dementia 25.5% of the variation in falls was explained by a model including "man walking with aid". Our results show that with the same set of common risk factors for falls a considerably lower proportion of the variation in falls can be explained in the group of people with dementia.