Results of the study indicate that perceived similarity of personality in same-sex adolescent friendships was marginally associated with higher quality ratings of friendship and significantly less conflict. Reciprocated friends perceived themselves to be more similar in personality than did non-reciprocated friends. This effect was mediated by the quality of friendship. These results can guide future research on similarity by highlighting potential mediating factors between variables such as reciprocity of friendship and perceived similarity. Similarity of personality and attitudes has been found to be associated with better quality relationships among adult romantic partners. However, similarity of adolescent friends' behavioral patterns, especially delinquent behaviors, such as drugs, has been well demonstrated. This study of a sample of 124 adolescents examined the role of perceived similarity of relevant developmental qualities, in order to better understand their association with friendship quality in early adolescence. Table and references