The current study explored the prediction of civic engagement by diverse trajectories of prosocial behaviors as well family dynamics (i.e., filial self-efficacy and relational parent-child support) across four times of assessment (from age 16-17 to age 22-23) during the transition to adulthood. Three different trajectories of prosocial behaviors were identified for 686 Italian youths: high-increasing (18%), medium-stable (48%), and low-stable (34%). An increasing pattern of change in prosocial behaviors was predicted by filial self-efficacy at age 16-17, which in turn mediated longitudinal relations to civic engagement and civic values at age 22-23. Results highlighted that during the transition to adulthood youths' beliefs about their ability to negotiate with their parents without losing autonomy and relatedness are relevant in promoting prosocial behaviors and civic involvement, especially in the context of Mediterranean countries.