Higher self-concept clarity is related to several adjustment indices and may be promoted by open communication with parents, while problems with self-concept clarity development could enhance internalizing problems (i.e., depressive and anxiety symptoms) in adolescence. This longitudinal study examined linkages between self-concept clarity, adolescents' open communication with parents, and adolescent depressive and anxiety symptoms. Dutch youths (N = 323; 51.1 % girls; mean age Time 1 = 13.3 years) reported on these constructs over four consecutive annual measurements. Concurrent positive links between open communication and self-concept clarity were found at Time 1. Over time, higher levels of open communication with parents predicted higher self-concept clarity only in middle adolescence (mean age between 14 and 15 years). We also found concurrent associations between self-concept clarity and both depressive and anxiety symptoms. Longitudinally, lower self-concept clarity predicted relatively higher levels of depressive symptoms across all waves, and also higher anxiety levels from Time 1 to Time 2. Conversely, higher levels of anxiety also predicted lower levels of self-concept clarity during the first three waves. Self-concept clarity did not mediate the longitudinal associations between open communication and internalizing symptoms. This study is one of the first to investigate self-concept clarity across adolescence. It highlights the possible importance of both anxiety symptoms and communication with parents in understanding the development of a clear self-concept, and demonstrates an association between lower self-concept clarity and higher levels of later depressive and anxiety symptoms.