The purpose of this research was to investigate the prevalence of peer harassment in preschool children and assess its influence on self-concept, hyperactivity, and behavioral problems. The participants were 4 and 5 year old children recruited from preschools and day care centers. Results indicated that a small group of children were identified as victims by self and teacher-reports. Negative self-concept and hyperactivity predicted self-reported victimization. In addition, hyperactivity, internalizing, and externalizing problems were significant contributors in teacher reported victimization.