Objective: To evaluate the clinical utility of the cutoff recommendations for the Vanderbilt ADHD Diagnostic Parent Rating Scale (VADPRS) comorbidity screening scales provided by the American Academy of Pediatrics/National Initiative for Children's Healthcare Quality and to examine alternative cutoff strategies for identifying and ruling out disorders commonly comorbid with attention-deficit/hyperactivity disorder. Methods: A sample of 215 children (142 with attention-deficit/hyperactivity disorder), ages 7 to 11 years, participated in the study. Parents completed the VADPRS and were administered a diagnostic interview to establish diagnoses of oppositional defiant disorder (ODD), conduct disorder (CD), anxiety, and depression. The clinical utility of the VADPRS comorbidity screening scales were examined. Results: The recommended American Academy of Pediatrics/National Initiative for Children's Healthcare Quality cutoff strategies did not have adequate clinical utility for identifying or ruling out comorbidities, with the exception of the VADPRS ODD cutoff strategy, which reached adequate levels for ruling out a diagnosis of ODD. An alternative cutoff approach using total sum scores was superior to the recommended cutoff strategies across all diagnoses in terms of ruling out a diagnosis, and this was particularly evident for anxiety/depression. Several individual items on the ODD and CD scales also had acceptable clinical utility for ruling in diagnoses. Conclusions: The VADPRS comorbidity screening scales may be helpful in determining which children likely do not meet diagnostic criteria for ODD, CD, anxiety, or depression. This study suggests that using a total sum score provides the greatest clinical utility for each of these comorbidities and demonstrates the need for further research examining the use of dimensional assessment strategies in diagnostic decision making.