The independent association of socio-economic position with self-reported disability was assessed. The effect of home and car ownership as additional indices of socio-economic position within occupational social classes was explored. Data from a prospective study of a cohort of 7735 men aged 40-59 years at recruitment and representative of the occupational social class distribution of middle-aged men in Great Britain were used. Men were selected from one general practice in each of 24 towns in England, Wales and Scotland in 1978-1980. The present study concerns 5773 (88.4% of those able to take part) men aged 52-73 years at follow up in 1992 who completed the disability section of a postal questionnaire. A quarter (1453) of men reported disability. Socio-economic position measured as both occupational class (social class I vs. V: age-adjusted OR 5.0, 95% CI 3.4-7.5) and ownership of home and car (both vs. neither: age-adjusted OR 2.8, 95% CI 2.3-3.4) showed a graded relationship with likelihood of reporting disability in 1992. Within all social class groups, those owning both home and car had a lower risk of disability than those who owned neither, even after adjustment for a wide range of risk factors. Men from manual occupations were more likely than those in non-manual occupations to report disability on developing chronic diseases. The relationship between socio-economic position and severe, but not milder, disability appeared to be independent of disease status. Socio-economic position is a strong predictor of disability in later life independent of a wide range of lifestyle factors and presence of diagnosed disease. The likelihood of reporting disability between and within social class groups is influenced by material wealth.