This study investigates the conceptual issues, theoretical rationale, construct validity, psychometric properties, and empirical analysis of the Self-Perception Profile for Adolescents (Harter, 1986). The scale was administered to 283 students (average age 13.1 years, 49% female) from 12 Year 7 classes in three non-selective systemic high schools. The scale assesses competence in 8 self-concept domains: scholastic competence, social acceptance, athletic competence, physical appearance, romantic appeal, conduct/morality, close friendships, job competence and, in addition, global self-worth. Separate items relating to mathematics and English abilities were added. The internal consistencies were generally high. Results from factor analysis provided strong support for the a priori dimensions, the multidimensional conceptualisation of the self-concept, thereby confirming Harter's (1985a) model.