Objective: To describe a patient who exhibited obsessive-compulsive disorder and frontal lobe dysfunction signs after a closed head trauma. Background: Recent evidence indicates that frontal-subcortical circuits are involved in the pathogenesis of primary obsessive-compulsive disorder. There are a number of case reports of secondary obsessive-compulsive disorder after lesions involving certain parts of these circuits. Method: Clinical examinations, cognitive and behavioral assessments, and lesion analysis based on magnetic resonance imaging were conducted. Results: The patient displayed marked obsessive-compulsive behavior along with hyperorality and apathy. Magnetic resonance imaging showed symmetrical frontal-polar abnormal signal intensity. Topographic lesion analysis revealed involvement of Brodmann areas 11, 10, 24, 25, and 32. Conclusions: The patient presented in this report had both frontal lobe dysfunction signs and obsessive-compulsive disorder secondary to bilateral frontal damage due to a closed head injury. The etiological significance of head injury and frontal lobe involvement in obsessive-compulsive disorder is discussed in the context of the clinical and neuroimaging findings and of previous series of brain injured patients.