The IOWA Conners and CASQ were administered to the entire population of children, grades K through 6, in a single elementary school. Using a whole-number IOWA Conners threshold score of 18 (1.5 SD), coupled with a CASQ score of 18 (1.0 SD), a high-risk group and an age-, sex-, and classroom-matched low-risk control group were selected for comparison on the Child Behavior Checklist (CBCL), Teacher's Report Form (TRF), Child and Adolescent Functional Assessment Scale (CAFAS), and Diagnostic Interview for Children and Adolescents-Revised diagnoses. The data show significant intergroup differences in CBCL (p greater than .0006), TRF (p treater than .0006), and CAFAS (p greater than .0002) scores and higher numbers of DSM diagnoses (1.7 plus or minus 0.3 versus 0.1 plus or minus 0.3 greater than .0007) between the high-risk and low-risk group. The positive predictive value for externalizing diagnoses for the IOWA Conners plus CASQ was 100 percent, and negative predictive value was 70 percent. The authors conclude that the IOWA Conners combined with the CASQ is a useful initial screening strategy in the school setting for identifying children with disruptive behavioral difficulties. 5 tables and 39 references