This study used the correlated trait-correlated method minus one model to examine the convergent and discriminant validity of the Child Behavior Checklist (CBCL), Teacher's Report Form (TRF) and Youth Self-Report (YSR), based on ratings of clinic-referred adolescents. A total of 294 adolescents, comprising 70.5 % males, provided self-ratings on the YSR. The adolescents were also rated by their mothers and teachers on the CBCL and TRF respectively. The findings indicated some support for convergent validity for the CBCL and TRF for Anxious/Depressed, Withdrawn/Depressed and Rule Breaking Behavior, and for the convergent validity for the CBCL and YSR for Rule Breaking Behavior. There was support for the discriminant validity between virtually all the traits. The findings are discussed in relation to the construct validity, cross-informant agreement, and clinical use of the CBCL, TRF and YSR.