YOUNG, D. R., D. S. SHARP, and J. D. CURB. Associations among baseline physical activity and subsequent cardiovascular risk factors.Med. Sci. Sports Exerc., Vol. 27, No. 12, pp. 1646–1654, 1995. To determine stability of cross-sectional associations between physical activity and cardiovascular risk factors and provide information regarding possible independent effects of physical activity on reduced cardiovascular disease, this report examined associations among baseline physical activity and risk factors measured over 15 yr. Subjects were 1,379 Honolulu Heart Program participants who were evaluated at baseline and three subsequent examinations. For men initially 45–54 yr, higher physical activity level was significantly associated cross-sectionally and at 2 yr with lower diastolic blood pressure, body mass index, and skinfold thicknesses, and at 5 yr with higher high density lipoprotein (HDL) cholesterol. By the 15-yr examination, only associations between physical activity level and skinfold thicknesses remained significant. For men 55–68 yr, significant cross-sectional and 2-yr associations were found between higher physical activity level and lower skinfold thicknesses, and higher HDL cholesterol at 5 yr. Higher physical activity continued to be associated with lower skinfold thicknesses and was related to lower systolic blood pressure by the 15-yr examination. Results suggest that most cross-sectional associations between physical activity and risk factors diminish over time, providing support for prospective investigations that find physical activity has a beneficial effect on reduced cardiovascular disease partially independent of traditional risk factors.