The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-lagged panel model of reciprocal effects between math self-concept and math anxiety. The analysis showed a reciprocal relationship between self-concept and anxiety in math (i.e., higher self-concept leads to lower anxiety, which in turn, leads to higher self-concept). However, the magnitude of the path from anxiety to self-concept is almost half of that from self-concept to anxiety. Overall, the results provide empirical support for the theoretical notion that math self-concept and math anxiety are reciprocally related. (Contains 1 table and 1 figure.)