The present study investigated mathematics performance and related interest value as the antecedents and consequences of teachers' causal attributions concerning children's academic outcomes during their kindergarten year. Sixty-nine children (5-6 years old at the baseline) and their teachers were examined twice during the kindergarten year. Children were tested in mathematics performance and interviewed about their interest value. Teachers rated their causal attributions in the fall and spring. The results showed that the higher the interest value in mathematics children showed, the more the teacher attributed their success to ability and effort. Teachers' ability attributions for success, in turn, contributed to an increase in children's interest value in mathematics. Moreover, attributing children's success and failure to external causes decreased children's mathematics-related interest value.