Professional or informal proxy respondents are frequently used in surveys when physical or mental health may compromise the ability to participate or the quality of responses. Functional status (Katz activities of daily living [ADL], Lawton instrumental activities of daily living [IADL]) was assessed in a sample of 420 chronically dependent elderly receiving home care. Separate in-person interviews were conducted with subjects, main informal caregivers and professionals coordinating home care. We found substantial agreement (Kappa) particularly between subjects and informal caregivers in all ADL except continence and in all IADL except housekeeping. High levels of agreement were also found for cognitively impaired subjects (Mini-Mental State Examination <24). Disagreement was characterized by more frequent reports of dependence from informal and professional caregivers. Our data suggest that proxy responses by informal caregivers conform with answers provided by subjects but produce slightly higher estimates of dependence and that cognitively impaired elderly living in the community will provide accurate information on their functional status in most cases.