The current study investigated the association between non-suicidal self-injury (NSSI), self-concept and acquaintance with NSSI peers in a sample of 150 high school students (60% female) with a mean age of 15.56 (SD=2.00) years. Analyses showed that students with NSSI rated themselves lower on academic intelligence, physical attractiveness, social skills and emotional stability than their non-NSSI peers. The self-injurers also had more friends who engaged in NSSI, and having more NSSI acquaintances was negatively related to self-esteem. It could be that adolescents with lower self-esteem are more attracted to self-injuring peers, or that adolescents with low self-esteem are more vulnerable to copy NSSI to deal with their problems or to gain a certain identity in their peer group. Future studies must test these possible NSSI pathways.