Health behaviours depend upon preferences and individuals’ assessments of the long-term costs and benefits to themselves and others. Concordance in health behaviours has been observed within households, but the mechanisms remain poorly understood. They may include a family health gatekeeper, selection, common influences, altruism, social learning and co-operation. We investigate these mechanisms by examining couple concordance in uptake of bowel cancer screening using the English Longitudinal Study of Ageing. We exploit the sharp age cut-off for screening programme eligibility at age 60 and use polynomial regression to study how initial screening participation depends upon partner’s uptake. We then examine whether the degree of concordance varies with both own and partners’ other health behaviours and characteristics. Individuals with non-screened partners are no more likely to participate in screening than comparable singles, whereas individuals with screened partners are 42 percentage points more likely to screen than individuals with a non-screened partner. Additionally, we find that previously non-screened individuals updated their screening behaviour if their younger partners participated in screening once they became eligible. These results and the patterns of heterogeneity in concordance suggest social learning and altruistic behaviour are the most likely mechanisms driving couple concordance. The findings have important implications for the optimal design of population-wide screening campaigns.