Statutory and voluntary social services provide care and support for vast numbers of vulnerable older adults, yet little is known about how social care practitioners respond to depression in this high risk population. This study elicited the perceptions and conceptualizations of this condition among social care staff, and views on how the response of social care and other agencies might be improved. Qualitative interviews were conducted with 20 social care practitioners working in generic services for older adults in south London. Depression was perceived to be remarkably common among clients, a phenomenon largely attributed to the adverse circumstances of old age, particularly social isolation. A key message from participants was that social causes indicate a need for social interventions. While primary care was criticised for not taking depression seriously in older people, mental health services were generally praised. Expansion of social, recreational and psychological interventions was advocated.