To test the reliability of children's reporting as compared with that of their mothers, a highly structured psychiatric diagnostic interview was used with 307 subjects, ages 6 through 16. Another interviewer gave each mother a similar interview about the child. Responses of each mother-child pair to 168 questions were compared using the kappa statistic. Highest agreement was found on questions concerning symptoms that are concrete, observable, severe, and unambiguous. Mothers tended to report significantly more behavioral symptoms, and children more subjective symptoms. Reasons for low kappas and asymmetrical reporting of symptoms are discussed.