Self-concept, or feelings about oneself, encompasses various areas including social and academic domains and has been suggested to be a predictor and mediator of other outcomes (Bryne, 1996). In this study, the relationships between achievement, intelligence scores, and self-concept in children with mild intellectual disabilities were examined. Self-concept and WISC verbal intelligence scores evidenced significant relationships. Additionally, relationships were demonstrated between gains in achievement and higher ratings of self-concept. These results suggest that relationships exist between intelligence, achievement, and self-concept in elementary school children with MID. Specifically, a positive relationship was demonstrated between achievement gains and self-concept. Associations between intelligence and self-concept also were demonstrated, where higher intelligence scores were related to both lower nonacademic self-concept and higher cognitive self-concept.