Objective: The aim of this study was to analyze the association between frequent headache and self-reported mental and physical work ability in a general population sample in Sweden. Methods: The study was conducted in western Sweden in 2008. Frequent headache was analyzed in relation to mental and physical work ability. Covariates included demographics and socioeconomic variables, work-related variables, and a symptom index. Self-reported and register-based sickness absence data were also analyzed. Results: Sixteen per cent of those who answered the question about headache (n = 2590) had frequent headache (at least once a week). Regression analyses showed that frequent headache sufferers were twice more likely to have poor mental and physical work ability than those having infrequent headache. Conclusions: Frequent headache was associated with poor mental and physical work ability but not with sickness absence. Copyright © 2014 by American College of Occupational and Environmental.