Previous studies have mostly focused on the socialisation role of parents on adolescents’ prosocial behaviours and there is relatively less work focusing on peers who are important socialisation agents for the development of prosocial behaviours in adolescence. Further, simultaneously examining the socialisation roles of multiple socialisation agents in prosocial behaviours and empathy development is even rarer. Thus, in the current study, we examined supportive and poor relationships with three socialisation agents (i.e., parents, peers in class, and peers in extracurricular activities) on adolescents’ prosocial behaviours, considering whether empathy mediates these relations. Additionally, we examined the links between supportive and poor relationships with peers in the class and extracurricular activities and adolescents’ prosocial behaviours, and the mediating role of empathy. The sample was 676 French adolescents (50% female, M age = 14.35 years). Supportive relationships and poor relationships models were tested separately. We examined the relative strengths of three socialisation agents using three-socialiser and two-socialiser models. In the three-socialiser model, supportive relationships with parents and peers in the extracurricular activities were positively linked to adolescents’ empathy a year later, which, in turn, was positively linked to helping and caring behaviours. Additionally, poor relationships with parents were negatively linked to adolescents’ empathy a year later, which, in turn, was positively linked to helping and caring behaviours. In the two-socialiser model, both supportive relationships with peers in class and extracurricular activities were positively linked to adolescents’ empathy 1 year later, which, in turn, was positively linked to helping and caring behaviours but only for early adolescents. Lastly, in the two-socialiser model, poor relationships with peers in extracurricular activities were negatively linked to adolescents’ empathy 1 year later, which, in turn, was positively linked to helping and caring behaviours. In general, these results were robust across adolescents’ gender and age. Overall, results make several important contributions to the literature on the role of multiple socialisation agents and adolescents’ prosocial behaviours.< Réduire