Objective: To investigate the relationship between overweight and obesity and sick leave. Design: Systematic, qualitative review. Literature search: A search in diverse databases was performed. Studies were considered as relevant if they were longitudinal in design and investigated the relationship between overweight and obesity and sick leave. Data extraction: The methodological quality of the studies was evaluated with a quality criteria list. To draw conclusions, a bestevidence synthesis was applied.Results: Thirteen studies were included. Four out of seven found overweight to be a predictor of long-term sick leave, whereas the remaining three showed a positive trend, but did not observe significance. Of the five studies investigating the relationship between overweight and short-term sick leave, inconsistent results were shown. Seven out of eight studies investigating the relationship with long-term sick leave found obesity as a significant predictor of long-term sick leave. In contrast, there were inconsistent results between the five studies examining the relationship between obesity and short spells of sick leave. Conclusions: Although this review found inconclusive evidence for a relationship between overweight and sick leave, a clear trend was discerned in that overweight was a predictor of especially long spells (47 days) of sick leave. As regards obesity, there was strong evidence for a positive relationship with sick leave because of the consistent finding that obesity was a significant predictor of long-term sick leave.