This study measured the association between duration of employment in piecework and the prevalence of severe disability among 533 Quebec female garment workers who left employment between 1976 and 1985. Yearly information regarding occupational characteristics was available from a public agency for the 30-year period 1956-1985. Information on disability status was collected in a personal interview. Duration of employment in piecework was associated with the prevalence of severe disability. A multivariate analysis found that the association was independent of age, smoking habits, education, type of task and total length of employment. Workers who spent 5-9, 10-14, 15-19, and greater than or equal to 20 years in piecework had an increased prevalence of severe disability in comparison with the base-line category of 0-4 years. The adjusted risk ratios were 2.2 [95% confidence interval (95% CI) 1.0-4.6], 3.3 (95% CI 1.5-6.9), 3.6 (95% CI 1.5-8.4), and 2.3 (95% CI 0.8-6.6), respectively. The association was particularly strong for disability due to musculoskeletal problems and disability due to cardiovascular disorders although small numbers were involved.