Threats to adolescent and young adult health and well-being come primarily from behavior and life choices. The purpose of this study was to understand the role that peer and parent relationships have on reckless and deviant behaviors during the transition from adolescence to emerging adulthood. Select Wave I and Wave III variables from the Add Health database were studied. Adolescent reckless behavior was significantly associated with emerging adult deviant behavior, Wald chi(2)(1, N = 4,615) = 105, p < .001, beta = 0.152, SE(beta) = 0.015 Adolescent reckless behavior increases the probability of emerging adult deviant behavior among adolescents having lower scores on the quality of peer relationships, Wald chi(2)(1, N = 4,615) = 56, p < .001, beta = 0.062, SE(beta) = 0.008, and the quality of parent relationships, Wald chi(2)(1, N = 4,545) = 36, p < .001 beta = 0.052, SE(beta) = 0.009.