Mr. X, a 44-year-old man, had suffered from OCD since adolescence. His obsessions included concerns about gaining weight in his abdomen and concerns about symmetry and exactness. His rituals included looking at his abdomen for a specified number of times, counting several numbers in his head before responding to questions, and repeating the same questions in a particular order. He ate little and compulsively rode his exercise bike in order to maintain the shape of his abdomen. He failed adequate trials of all SSRIs, SNRIs, clomipramine, and augmentation with antipsychotic agents. His isolation made cognitive behavior interventions impracticable. He was on a high daily doses of phenelzine (135 mg/day), clonazepam (8 mg/day), lamotrigine (450 mg/day), and topiramate (400 mg/day). Phenelzine was gradually lowered to 75 mg/day, while the rest of his medication was unchanged. Syndrome severity and failure of conventional pharmacotherapy led to the decision to use riluzole, with the rationale that this agent down-regulates glutamatergic neurotransmission through a mechanism different from those of lamotrigine and topiramate. The initial dose was 25 mg/day, with the plan to increase the dose by 25 mg per week, to the target dose of 100 mg/day. About 1 week after the introduction of riluzole, he began to improve. He spent less time looking at his abdomen. His food intake improved. He was able to articulate his questions in a nonstereotypical manner and participate in group therapy.