This study investigated the self-concept of 150 college preparatory students in grades 10, 11 and 12. The independent variables were gender, educational classification (grade level), residency status, involvement in extracurricular activities, family structure, and family concept. The dependent variable was the self-concept score obtained from the Personal Attribute Inventory-Self. Subjects completed a demographic data sheet, an activity involvement rating sheet, the Personal Attribute Inventory-Self, and the Personal Attribute Inventory-Family. Three significant main effects were found for residency status, involvement in extracurricular activities, and family structure. Two significant interactions were found between involvement in extracurricular activities and family structure and between family structure and family concept. The findings suggest: that students who lived at home with parents had stronger self-concepts than those with other living arrangements; that students highly involved in extracurricular activities had stronger self-concepts than all other subgroups except those from intact families with low involvement; that students from other family structures with intermediate and low involvement in extracurricular activities had the weakest self-concepts; and that students from intact family structures reporting both positive and negative family concepts had stronger self-concepts than those from other family structures, regardless of family concept. (Author/NB)