Few researchers have investigated the resting pulse rate of children and young adults as a risk factor or indicator for subsequent cardiovascular morbidity in a representative sample of the total population. Data from the first National Health and Nutrition Examination Survey for persons ages 6-24 years revealed mean resting pulse rates that declined with age until ages 12-16, were higher in females than males, and in whites than blacks. At ages 12-17 and 18-24, blood pressure and body temperature showed consistent, independent, positive associations with pulse rate in whites. However, relatively little of the overall variation in pulse rate was explained by measured variables in multivariate regression analyses. Mother-child, age-specific correlation coefficients for pulse and blood pressure were generally positive. Further research is needed on the associations of resting pulse rate with sex, race, and blood pressure and with subsequent cardiovascular morbidity.