This study examined maternal and early adolescent temperament dimensions as predictors of maternal emotional behavior during mother-adolescent interactions. The sample comprised 151 early adolescents (aged 11-13) and their mothers (aged 29-57). Adolescent- and mother-reports of adolescent temperament and self-reports of maternal temperament were collected. Mother-adolescent dyads participated in event-planning and problem-solving interactions, which were coded for frequency of aggressive, dysphoric, and positive interpersonal maternal behavior. Analyses indicated that adolescents who are higher in temperamental Negative Affectivity and lower in Effortful Control are generally exposed to more frequent aggressive and less frequent positive interpersonal maternal behavior. Furthermore, mothers lower in Effortful Control engaged in more frequent dysphoric behavior toward their adolescent. Given the associations between parental emotional behavior and the development of adolescent emotion regulation, these findings suggest that temperamental dispositions, particularly of early adolescents, may influence their ongoing socialization of emotion regulation skills, and thus their emotional well being. (Contains 3 tables.)