Confirmatory Factor Analysis (CFA; LISREL) was used to: (1) validate the Self Description Questionnaire III (SDQ III) subscales measuring general, school, English, and mathematics self-concepts for a sample of 898 (285 low track and 613 high track) students in grades 11 and 12, and (2) test the equivalency of the factor structure across academic tracks. The results confirm a four-factor structure and reveal all factor loadings and covariances to be invariant across groups; 11 of 21 uniquenesses were non-invariant. Although, in a strict statistical sense, the differentially reliable items bore implications of bias in favor of the high track, these discrepancies, on the basis of absolute values, were judged to be of little practical significance. Overall, in light of the stringency of LISREL CFA procedures in general, and those used in this study in particular, the SDQ III demonstrated exceptionally superior psychometric properties. (Author)