There is a lack of information on how cognitive ability relates to both health behaviors and change in health behaviors over time. This study examined verbal ability and processing speed as predictors of health behaviors in the PATH Through Life Study that includes cohorts aged in their 20s, 40s and 60s. Higher cognitive scores were associated with higher levels of physical activity, greater likelihood of taking vitamin and mineral supplements, reduced likelihood of current smoking and not abstaining from alcohol. However, lower level of verbal ability and processing speed were associated with higher levels of use of cholesterol lowering medication in the 60s cohort. Physical activity, consumption of vitamins and minerals and taking cholesterol lowering and antihypertensive medication over the four-year follow-up period increased in this cohort. The likelihood of adopting healthier behaviors was greatest for those with the lowest cognitive scores. We conclude that while higher levels of cognitive performance are associated with health promoting behaviors, improvements in health behavior are more likely to be due to non-cognitive, contextual and societal factors. (Contains 4 tables.)