The aim of this study was to assess the relationship between frailty and a large number of indicators related to physical and muscular performance as well as quality of life. This is an analysis of data collected at baseline in the Sample of Elderly Nursing home Individuals: an Observational Research (SENIOR) cohort including nursing home residents. Subjects are volunteer, oriented and able to walk (walking assistance allowed) nursing home residents in Belgium. A large number of demographic and clinical characteristics, including physical and muscular performance, were collected from each patient. The prevalence of frailty in this population was assessed using Fried's definition. In total, 662 subjects are included in this analysis. The mean age of the sample is 83.2±8.99years, and 484 (73.1%) are women. In this population of nursing home residents, the prevalence of frailty is 25.1%, pre-frailty, 59.8% and robustness, 15.1%. Compared to non-frail subjects, frail subjects have lower physical and muscular performances and a lower quality of life. Frailty, according to Fried's definition, seems to be associated with several clinical indicators suggesting a higher level of disability and an increased propensity to develop major clinical consequences. Follow-up data of the SENIOR cohort will be helpful in confirming these findings, establishing cause-effect relationships and identifying the most predictive components of physical frailty for adverse outcomes in nursing homes.