Peer victimization is an enduring problem in schools (Wang, Iannotti, & Nansel, 2009). The current study focused on relations among two ecological variables that may be related to involvement in peer victimization: self-concept and social support. The main goal of this study was to investigate relations among social support, self-concept, and involvement in peer victimization (both as a victim and aggressor). The sample included 251 students in Grades 3-5. There was a significant negative relation between social support and peer victimization ([beta] = -0.22, p less than 0.05) as well as a significant, negative relation between self-concept and peer victimization ([beta] = -0.24, p less than 0.05). For peer aggression, there was a significant negative relation between social support and peer aggression ([beta] = -0.49, p less than 0.001) as well as a significant, positive relation between self-concept and peer aggression ([beta] = 0.23, p less than 0.05). (Contains 4 tables and 4 figures.)