Longitudinal research on the links between intelligence and health behaviors among adolescents is rare. We report longitudinal data in which we assessed the relationships between intelligence as assessed in Grade 7 and consequential health outcomes in Grade 11. The mean age of respondents (N = 420; 188 males, 232 females) was 12.30 years (SD = 0.49) in Grade 7and 16.17 years (SD = 0.45) in Grade 11. They completed standardized verbal and numerical ability tests and a measure of conscientiousness in Grade 7 and health related questions in Grade 11. Results indicated that higher intelligence was associated with a number of healthy behaviors including delay in onset of cigarette smoking. Intelligence significantly predicted less time spent watching TV, lower physical exercise, and lower consumption of stimulant drinks. Covariate analyses showed that general intelligence predicted health outcomes after controlling for conscientiousness, socio-economic status, and gender.