The self-concept is closely associated with various cognitive, emotional, and behavioral outcomes (e.g., physical activity; Craven & Marsh, 2008). One of the most salient and influencing sources of self-concept in childhood are school grades as they are directly communicated and easy to compare (Arens et al., 2017). Several studies have supported reciprocal relationships between academic self-concept and academic achievement (Huang, 2011). However, the relationship between different self-concept domains (e.g., physical and native language self-concept) and self-esteem considering the grades in the associated areas (e.g., physical education and native language) is still unclear. Therefore, the aim of this study was to examine the meaning of grades for a) the level of associated self-concepts and b) the relationship of self-concept domains with self-esteem. 236 students from class 6 to 8 (range: 11-14 ys.) participated in the study (class 6: n = 86, class 7: n = 73, class 8: n = 82). Physical self-concept was assessed using the PSK (Stiller et al., 2004), native language self-concept was measured with a questionnaire by Arens and Jansen, 2016). Student's self-esteem was assessed by a German version of the SDQ I (Arens et al., 2011). Results show a main effect of grades on the level of both self-concept domains, physical and native language. Besides, the self-esteem is stronger related to physical self-concept than to native self-concept, especially in children who are better in physical education. As other relations are still found as inconsistent, the role of grades for self-concept development in early adolescence is discussed.