Applying latent growth curve analysis to a sample of 310 adolescents, this study demonstrates that level of and changes in observed parental behavior are liked to the level of and changes in adolescent physical health status, respectively, through adolescent perception of parental support. In addition, the level of observed parental behavior had a significant direct effect on subsequent changes in adolescent health status. The results provide evidence for the influence of parental support on adolescent physical health, both directly and indirectly through the adolescent's perception of that support. Confidence in the findings is strengthened by (1) employing a prospective, longitudinal research design, (2) analyzing intraindividual changes in support and health, and (3) reducing potential method variance confounds by using multi-informant reports of parental behavior.