The present study investigated whether kindergarten teachers' causal attributions would predict children's reading-related task motivation and performance, or whether it is rather children's motivation and performance that contribute to teachers' causal attributions. To investigate this, 69 children (five to six years old at baseline) and their teachers were examined twice during the kindergarten year. Teachers filled in a questionnaire measuring their causal attributions twice during the kindergarten year. Information about the children's reading-related task motivation and performance was gathered at the beginning of and at the end of the kindergarten year. The results showed that the higher the task motivation and performance in reading the children showed, the more the teachers attributed their success to ability and effort, and the less they attributed it to teachers' help. Teachers' ability and effort attributions for success, in turn, predicted a high level of children's subsequent task motivation in reading. Moreover, teachers seldom attributed high-achieving children's failure to lack of ability or effort.