Conduct disorders are the most frequent psychiatric diagnosis in the pediatric and adolescent population, with different etiology and difficult to treat. Delinquent, aggressive, and impulsive behavior, lack of empathy and inability to predict possible consequences of the behavior lead to significant desadaptation and danger for these patients. In clinical practice, focus is usually given on social and psychological causes of conduct disorders ignoring possible biological factors in etiology and pathophysiology. A clinical case described in this article shows the linkage between frontal brain dysfunction and behavioral symptoms. The first clues of organic brain disorder were multiple and severe symptoms of disinhibition resistant to treatment with dopaminergic drugs and the results of neuropsychological testing. Computed tomography, magnetic resonance imagining, and single-photon emission computed tomography findings were minor and not supported by associated neurological symptoms. However, the location of alterations of brain structure and perfusion significantly correlated with psychopathology. Clarification of the organic cause of the conduct disorder allowed choosing an effective strategy of psychopharmacologic treatment. A positive clinical effect was achieved after switching the treatment from dopaminergic antipsychotic drugs to carbamazepine, which modulates the GABAergic system. Presenting this clinical case, we intended to emphasize the importance of careful attention to the findings of neurovisual and neuropsychological testing diagnosing conduct disorders and individually choosing the most effective psychopharmacologic treatment.