BACKGROUND: Religious belief can be used as a pain coping strategy. Our purpose was to evaluate the relationship between headache and religious activity using prospective data from a large population-based study. METHODS: This longitudinal cohort study used data from two consecutive surveys in the Nord-Trøndelag Health Survey (HUNT 2 and 3) performed in 1995-1997; and 2006-2008. Among the 51,383 participants aged ≥ 20 years who answered headache questions at baseline, 41,766 were eligible approximately 11 years later. Of these, 25,177 (60%) completed the question in HUNT 3 regarding religious activity. Frequent religious attendees (fRA) (used as a marker of stronger religious belief than average) were defined as those who had been to church/prayer house at least once monthly during the last six months. RESULTS: In the multivariate analyses, adjusting for known potential confounders, individuals with headache 1-14 days/month in HUNT 2 were more likely to be fRA 11 years later than headache-free individuals. Migraine at baseline predisposed more strongly to fRA at follow-up (OR = 1.25; 95% CI 1.19-1.40) than did non-migrainous headache (OR = 1.13; 95% 1.04-1.23). The odds of being fRA was 48% increased (OR 1.48; 95% 1.19-1.83) among those with migraine 7-14 days/month at baseline compared to subjects without headache. In contrast, headache status at baseline did not influence the odds of being frequent visitors of concerts, cinema and/or theatre at follow-up 11 years later. CONCLUSIONS: In this prospective study, headache, in particular migraine, at baseline slightly increased the odds of being fRA 11 years later.