This study assessed factors associated with functional disability in old age in Greater Metropolitan Belo Horizonte, Minas Gerais State, Brazil. The theoretical model was based on predisposing (socio-demographic), extra-individual (social support, use of health services), and intraindividual factors (health conditions). The study was conducted in a probabilistic sample of 1,786 subjects aged = 60 years. The dependent variable was disability defined as mild (some difficulty) or severe (total dependence) in performing at least one basic activity of daily living. Prevalence of disability was 16% (8% mild; 8% severe). Age and worse self-rated health were independently and positively associated with mild and severe disability. Self-reported hypertension and arthritis were associated with mild disability, while diabetes and stroke were associated with severe disability. Severe disability was independently and negatively associated with number of visits by friends in the previous 30 days. According to the results, chronic conditions associated with disability in the study population are preventable, and severely disabled elderly had less extra-family social support.