Recognizing the ageing of populations and expected increase in prevalence of dementia, the necessity of research involving persons with dementia is widely agreed upon. Autonomy is key to nursing home residents' well-being and quality of life, but this phenomenon has not been thoroughly assessed from the residents' perspective. The aim of this cross-sectional study was to investigate perceived autonomy of nursing home residents. Data on 560 randomly selected residents in 40 nursing homes in two German federal states were generated by face-to-face interviews, psychological and physical assessments, analysis of nursing records, and acquisition of institutional parameters. This paper reports on a subsample (n = 179) that met screening requirements, including subjects with and without mild cognitive impairment (Mini Mental Status Examination score 30-18), who completed the Hertz Perceived Enactment of Autonomy Scale (HPEAS). The mean score of HPEAS was 101.1 ± 14.5 (range 54-122). In our population, Cronbach's alpha was 0.89. Scores in HPEAS were not related to demographical factors but positively associated with increasing self-efficacy and absence of pain. The novel findings contribute to an understanding of autonomy from the residents' perspective.