Temperament has drawn considerable attention in the understanding of behavioural problems and psychopathology across developmental stages. However, less of a focus has been placed on the role of temperament in physical aspects of health. We aimed to examine the relations between early temperament traits and physical health in school-age children. This study used longitudinal data of 18,994 children (52.4% boys) born in 2005 from the Taiwan Birth Cohort Study, in which follow-up surveys were conducted via face-to-face interviews with the child’s caregiver. Temperament at 5.5 years of age was assessed using a nine-item measure, and two higher-order temperament traits, surgency and regulation, were derived through confirmatory factor analysis. Physical health outcomes at age 8 included caregiver-rated general health status and medically attended injuries. Multiple logistic regression analysis was applied, with the child’s birth outcome, early health status or injury history, health behaviours and family socioeconomic status as control variables. The results indicated that higher levels of surgency and regulation, as early temperament traits, significantly predicted lower odds of caregiver-rated poor health in later years. Higher level of regulation was also associated with lower odds of injury risk. Our findings suggest that assessing early temperament traits could be useful for the promotion and management of physical health in young school-age children.