Background: Musculoskeletal pain is one of the most common causes of sickness absence. Sleep disturbances are often co-occurring with pain, but the relationship between sleep and pain is complex. Little is known about the importance of self-reported sleep, when predicting sickness absence among persons with musculoskeletal pain. This study aims to study the association between self-reported sleep quality and sickness absence 5 years later, among individuals stratified by presence of lower back pain (LBP) and neck and shoulder pain (NSP). Methods: The cohort (n = 2286) in this 5-year prospective study (using data from the MUSIC-Norrtalje study) was stratified by self-reported pain into three groups: no LBP or NSP, solely LBP or NSP, and oncurrent LBP and NSP. Odds ratios (ORs) for the effect of self-reported sleep disturbances at baseline on sickness absence (> 14 consecutive days), 5 years later, were calculated. Results: Within all three pain strata, individuals reporting the most sleep problems showed a significantly higher OR for all-cause sickness absence, 5 years later. The group with the most pronounced sleep problems within the concurrent LBP and NSP stratum had a significantly higher OR (OR 2.00; CI 1.09-3.67) also for long-term sickness absence (> 90days) 5 years later, compared to the group with the best sleep. Conclusions: Sleep disturbances predict sickness absence among individuals regardless of co-existing features of LBP and/or NSP. The clinical evaluation of patients should take possible sleep disturbances into account in the planning of treatments.