Introduction: Youth with callous-unemotional (CU) traits show severe and chronic forms of antisocial behavior, as well as deficits in socioaffiliative processes, such as empathy, guilt, and prosocial behavior. Adolescence represents a critical developmental window when these socioaffiliative processes can help to deepen the strength of supportive peer friendships. However, few studies have explored the relationship between CU traits and friendship quality during adolescence. In the current study, we used data from the Pathways to Desistance dataset to examine reciprocal and longitudinal associations between CU traits and friendship quality at three assessment points separated by 6 months each during adolescence. Methods: The sample included adolescents who had interacted with the justice system (age at baseline, M = 16.04, SD = 1.14; N = 1354; 13.6% female). CU traits were assessed using the callousness scale of the self-reported Youth Psychopathic Traits Inventory and friendship quality using a scale adapted from the Quality of Relationships Inventory. Models accounted for cooccurring aggression, impulsive-irresponsible traits, grandiose-manipulative traits, age, gender, location, and race. Results: At every assessment point, CU traits were uniquely related to lower friendship quality. Moreover, we found evidence for reciprocal effects between the first two assessment points, such that CU traits were related to decreases in friendship quality over time, while lower friendship quality simultaneously predicted increases in CU traits across the same period. Conclusions: Interventions for CU traits could benefit from including specific modules that target the social processes associated with adaptive and successful friendships, including empathic listening and other-orientated thinking.A large body of research has established the importance of adolescent friendships for the development of successful adult relationships and socialization (