OBJECTIVES: Although sickness absence is a strong predictor of health, whether this association varies by occupational position has rarely been examined. The aim of this study was to investigate overall and diagnosis-specific sickness absence as a predictor of future long-term sub-optimal health by occupational position. METHODS: This was a prospective occupational cohort study of 15 320 employees (73% men) aged 37-51. Sickness absences (1990-1992), included in 13 diagnostic categories, were examined by occupational position in relation to self-rated health measured annually during 1993-2006. RESULTS: 60% of employees in higher occupational positions and 22% in lower positions had no sickness absence. Conversely, 9.5% of employees in higher positions and 40% in lower positions had over 30 sick-leave days. Repeated-measures logistic regression analyses adjusted for age, sex and chronic disease showed employees with over 30 days absence, compared to those with no absence, had approximately double the risk of sub-optimal health over the 14-year follow-up in all occupational positions. 1-30 days sick-leave was associated with greater odds of sub-optimal health in the high (OR 1.48; 95% CI 1.27 to 1.72) and intermediate (1.29; 1.15 to 1.45) but not lower occupational positions (1.06; 0.82 to 1.38). Differences by occupational position in the association between sickness absence in 13 specific diagnostic categories and sub-optimal health over the ensuing 14 years were limited to stronger associations observed with cancer and mental disorders in the higher occupational positions. CONCLUSIONS: The association between sickness absence of more than 30 days over 3 years and future long-term self-rated health appears to differ little by occupational position.