Parental and peer influence on adolescents account for a substantial portion of the variation in health behavior developing in late adolescence. Of high school students sampled, 50% describe the influence attempts of their mothers, fathers and peers as neutral on most health behavior. Smoking is the exception to the pattern with mothers and fathers strongly discouraging and peers mildly encouraging smoking. Peer and parental influences are consistent with each other regarding weight watching, health food selection and optional exercise. The most frequent response for these behaviors, other than neutral, is that of mild encouragement. It seems clear that there is the potential for health educators, government health agencies and others to increase efforts to involve parents and peers in more actively influencing the establishment of health maintaining habits in adolescents. (BN)