The present paper describes the development and empirical validation of a German-language questionnaire for measuring the self-concept of lower secondary students from special schools and from regular school types. On the basis of the German version of the Self-Description Questionnaire I (SDQ I; Arens, Trautwein, & Hasselhorn, 2011), we developed eight scales with 38 items. These should economically measure multiple facets of self- concept and be usable in high, intermediate, and lower tracks as well as in special schools (area of learning). Test analyses were performed on the database of a total sample of N = 1907 students of different school types (n = 294 students at special schools). Confirmatory factor analyses confirmed the predicted structure of the scales. Measurement invariance across gender and school type was established. The key findings of international studies on the structure of self- concept could be replicated. Significant correlations between the scales and external criteria provided evidence for the validity of the instrument. Reliability estimates were generally high (ranging from alpha= .84 to alpha= .91).