There are few studies on parental socialization of positive emotions in adolescents and few instruments that measure these parental reactions. Therefore, we developed a new version of the Emotion Socialization Scale (ESS) for the positive emotion of overjoy. We further provided some evidence of validity and reliability of the Portuguese ESS, featuring overjoy, fear, anger, and sadness. Adolescents (N = 418) answered questionnaires on maternal emotion socialization and maternal rearing practices. Confirmatory factor analysis achieved good (reward, neglect, override, magnify) to acceptable (punish) levels of fit, and scales had good levels of internal consistency, except for punish (all emotions) and neglect (overjoy). Association with maternal rearing practices supported the adaptive role of reward and magnify and the less adaptive role of punish, override, neglect of positive emotion, with some exceptions. This investigation demonstrated the importance of assessing parents' reactions to adolescents' positive emotion as these may be important indicators of the parent-adolescent relationship quality. [ABSTRACT FROM AUTHOR]