BACKGROUND: Providing everyday activities is central to high quality residential aged care, but further research is needed on the association between activity participation, person-centred care and quality of life. AIMS AND OBJECTIVES: To explore the point-prevalence of participation in everyday activities for residents with dementia within a national sample of Swedish residential aged care units and to explore if residents participating in everyday activities lived in more person-centred units and/or had higher quality of life as compared to residents not participating in everyday activities. DESIGN AND METHODS: A cross-sectional design was used to collect valid and reliable questionnaire data on activity participation, unit person-centredness and quality of life in a sample of residents in residential aged care (n = 1266). RESULTS: Only 18% of residents participated in everyday activities such as making coffee, setting or clearing the table, cleaning or watering plants, 62% participated in outdoor walks, 27% participated in parlour games, and 14% and 13% participated in excursions and church visits, respectively. Those residents who had participated in everyday activities lived in more person-centred units, had significantly higher quality of life and higher cognitive scores as compared to those residents who had not participated in everyday activities. CONCLUSIONS: Even though the prevalence of resident participation in everyday activities was low, resident participation was significantly associated with unit person-centredness and resident quality of life. It seems that everyday activities that are routine and commonplace to residential aged care can be potent nursing interventions for promoting resident quality of life.