Objective: To examine the reliability of the French Diagnostic Interview Schedule for Children (DISC-2.25) in Quebec in light of other DISC-2 studies conducted in the National Institute of Mental Health's Methods for the Epidemiology of Child and Adolescent Mental Disorders Study. Method: Reliability was assessed for DSM-III-R disorders in a community sample comprising 260 parents of youths aged 6 to 14 years and 145 adolescents aged 12 to 14 years. The DISC was completed at home. The mean test-retest interval was 13.8 days for parents and 12.8 days for adolescents. Results: Parents' reports: Internal consistency was acceptable for a majority of disorders. The coefficients were in the fair or good ranges except for depressive disorders and were higher for children than for adolescents, and intraclass correlations were higher than coefficients. Adolescents' reports: Internal consistency was acceptable or nearly acceptable for a majority of disorders. The coefficients were in the fair range, and intraclass correlations were higher than coefficients. The coefficients were significantly higher for the test-retest interval of 7 to 14 days than for 14 to 21 days for adolescents' reports of anxious disorders and internalizing disorders. Conclusion: The French DISC-2.25 shows acceptable internal consistency and fair to good test-retest reliability. Across DISC-2 studies, test-retest reliability of the parents' reports improved for anxiety and depressive disorders. Among sources of variation, studies on attributes of questions would be meaningful.