In more than 15 years of working with older people, in community settings and in health, one of the more common triggers for social work involvement centred around issues of competency – the capacity of the older person to continue to exercise autonomy and self determination in any or all facets of his/her life. Social workers operate within defined ethical guidelines, one of which is to recognise and uphold the dignity of the individual and the individual’s right to autonomy. However, often there is tension between the twin values of upholding this right to autonomy and the duty of care when working with older people where there is a question of impaired cognition and decision-making capacity. This article explores that tension in terms of the social work response.