Maternal hostility/rejection and warmth were considered as potential mediators of the relation between mothers' and adolescents' emotion regulation. Participants were first-year high school students living in Ankara, Turkey and their mothers (N = 365). Scales assessing emotion regulation difficulties and maternal hostility/rejection and warmth were administered to both the adolescents and their mothers. Maternal hostility/rejection, but not warmth, mediated the relation between maternal and adolescent emotion regulation. For girls there was, additionally, a direct effect of maternal emotion regulation. The different roles played by parental rejection and parental warmth in the development of adolescents' emotion regulation accord with arguments that socialization occurs in different domains and that rejection and warmth are not aspects of the same domain. (C) 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.