Background: This study examines the use of the Brief Child and Family Phone Interview (BCFPI) to screen for childhood psychiatric disorder based on Diagnostic Interview Schedule for Children Version IV (DISC-IV) classifications of attention-deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), conduct disorder (CD), separation anxiety (SAD), generalized anxiety (GAD) and major depression (MDD). Methods: Data for analysis come from a sample of 399 children and adolescents aged 5-17 years old referred to child mental health outpatient services in three Ontario cities. Mothers were administered the BCFPI on three occasions: baseline, 2 and 13 months; and the DISC-IV on two occasions: 1 and 12 months. Results: Based on kappa, test-retest reliability for disorders classified by the BCFPI exceeded 0.50 for all conditions except MDD (0.45). In receiver operating characteristic (ROC) analysis, area-under-the-curve (AUC) estimates for BCFPI scale score associations with DISC-IV classifications of disorder exceeded 0.80 for CD, ODD, ADHD and SAD; and were lower for GAD (0.76) and MDD (0.75). In stratified analyses, there were no statistically significant differences in AUC estimates for boys versus girls and 5 to 11 versus 12 to 17-year-olds. Conclusions: Classifications of childhood disorder derived from the BCFPI provided a reasonable approximation to disorders classified by the DISC-IV administered by lay interviewers.