There is a high rate of comorbidity between psychiatric and neurodevelopmental disorders, which greatly complicates accurate diagnosis and effective treatment. The comprehensiveness of a multi-disciplinary approach overcomes the limitations of any one discipline, and ensures a maximized developmental outcome for each child patient. This Clinical Case Conference uses cases to highlight the frequency of co-occurrence between psychiatric and neurodevelopmental disorders; to identify challenges and barriers to accurate diagnosis in this population; to illustrate the potential adverse consequences of incomplete or inaccurate identification of these problems, including significant maladjustment, morbidity, severe school difficulties and misinterpretation of the child’s behavior by both school teams and families; and finally, to emphasize the importance of multi-disciplinary collaboration in treatment planning.