Based on Weiner's attributional theory of intrapersonal motivation, the mediating effect of attributions between teacher judgment and student motivation was examined. In two studies, 144 German and 272 Chinese fourth-grade elementary school students were tested on their mathematical achievement, causal ascriptions for success and failure, expectancy for success, self-concept, and test anxiety. Mathematics teachers were asked to estimate students' performances on the applied mathematics test. Discrepancies between teacher judgment and student performance led to groups of underestimated and overestimated students. One year later, Chinese students were retested on their mathematical achievement. Results show that the attributional pattern of underestimated students was maladaptive compared with overestimated students. Attributions mediated the effect of teacher judgment on students' expectancy for success, self-concept, test anxiety, and, in case of the Chinese sample, mathematics achievement of the next year. The results indicate the important role of student attributions as a function of teacher judgment and imply attribution retraining as a possible intervention.