Future time perspective (FTP) has been associated with positive outcomes in adolescents' development across different contexts. However, the extent to which FTP influences adaptation needs additional understanding. In this study, we analysed the relationship between FTP and adolescents' behavior in school, as expressed in several indicators of achievement, social integration, and overall satisfaction. We also considered the mediating role of FTP in the association between socioeconomic status, defined by parental education, and adolescents' behavior in school. The sample consisted of 349 Portuguese adolescents, ranging in age from 14- to 18-years-old. We used a self-report measure of FTP and a school life survey. Regression analyses and bootstrapping procedures revealed that FTP was a significant predictor of school adaptation and a mediator of parental education influence on several adaptation variables. We discussed the results regarding the broader role of FTP in adaptive behavior as well as the importance of school counseling services aimed at fostering adolescents' FTP.