Objectives: We tested the diagnostic efficiency of the DSM-oriented Child and Adolescent Symptom Inventory (CASI-4) ADHD symptom subscales for screening ADHD Combined, Hyperactive-impulsive and Inattentive subtype in a pediatric outpatient sample. Methods: Participants were 707 first-time utilizer at nine outpatient mental health clinics aged 6.0-12.9 years (M = 9.36, SD = 1.90) who completed the baseline Longitudinal Assessment of Manic Symptoms study assessments. Consensus diagnoses were based on KSADS interviews of both youth and caregivers. Caregivers completed the CASI-4 ADHD subscales Inattention, Hyperactivity and Combined as predictors. To maximize clinical utility we report diagnostic likelihood ratios (DLRs). Results: Using receiver operating characteristic analysis, the Area under the Curve (AUC) for the Combined subscale was .79 (95 % CI .78 - .81) for screening ADHD-Combined. CASI-4 Hyperactivity subscale AUCs for screening ADHD-Hyperactive-impulsive and ADHD-Combined were .70 (95 % CI .66 - .76) and .82 (95 % CI .80- .84) respectively. CASI-4 Inattentive subscales AUCs for screening ADHD-Inattentive and ADHD-Combined were .77 (95 % CI .74 - .79) and .71 (95 % CI .69 - .73). ROC curve tests comparisons will be provided. A cut score of 40 + was identified as the optimal threshold (DLR of 3.7) for screening ADHD-Combined with the CASI-4 Combined in children ages 6-13 seen in outpatient settings. Conclusions: CASI-4 ADHD subscales are clinically useful to screen for ADHD symptoms in children because of their brevity and economy. However, clinicians should be cautious when interpreting results and should include other data to reach an accurate diagnosis.