L’attaccamento ai genitori ed ai pari come fonte di benessere sociale: un’analisi delle differenze di genere - Parental and peer attachment as a source of social well-being A growing body of evidence reveals that adolescents and emerging adults strongly attached to parents and peers report high psychological well-being. Less investigated is the association between the quality of attachment and the perception of social well-being, that is the evaluation made by individuals of the quality of their life and their function in the society. Therefore, the purpose of this research was to investigate if high parental attachment promotes social well-being by means of the mediation of peers attachment, and to examine if these relationships are moderated by gender and age. The participants were 346 individuals (51% males): 186 adolescents and 160 university students . The hypothesized model was tested through structural equation modelling. Findings indicated a very good fit of the model. The multi-group comparison revealed significant differences between boys and girls. In males a good parental attachment promotes social well-being through the mediation of peer attachment. Whereas, in females parental attachment influences social well-being both directly and indirectly, by means of peer attachment. Furthermore, as individuals grew older the influence of the peer attachment on social well-being increased. Key words: attachment theory, adolescence, psychological well-being, structural equation modelling.