Considering the relevance of the affective dimension of the psychopathic personality in developmental and predictive models of youth conduct problems, the Inventory of Callous-Unemotional traits (ICU) has been developed as a reliable and effective measure of callous–unemotional traits (CU) in childhood and adolescence. The main purpose of the present study was to examine the relevance of CU traits, measured through the parent and self-report versions of the ICU, in a Spanish sample of 138 adolescents aged 12–17. Moreover, we analyzed the potential contribution of early parenting practices, measured in a six-year earlier study, to adolescent CU traits. Assuming the three factor structure validated in previous research (callousness, uncaring and unemotional), results showed the expected associations of ICU scales and other psychopathic and more general personality traits, as well as with a wide range of external behavioral and psychosocial criteria. At the subscale level, relevant distinctive associations were observed, with some problems detected on the unemotional subscale. Finally, interesting preliminary associations were identified among early parenting practices and adolescent CU traits, with the highest levels of CU observed in youths from authoritarian families. Those results support the usefulness of the ICU in adolescent samples, highlighting the relevance of CU traits in relation to adolescent behavioral and psychosocial adjustment as well as the role of early parenting practices in, and providing a new international scope on the topic.