Home care recipients have reported little self-determination and opportunity to influence their own care. Person-centred care focusing on involvement has improved the quality of life of older adults in health care and nursing homes; however, knowledge about the effects of person-centred interventions in aged care at home is sparse. The aim of this study was to study the effects of a person-centred and health-promoting intervention, compared with usual care, on health-related quality of life, thriving and self-determination among older adults, and on job satisfaction, stress of conscience and level of person-centred care among care staff.