Hypersensitivity syndrome is a rare but potentially fatal reaction to some pharmacologic agents, including some antiepileptic drugs. Typically, the syndrome presents with fever, rash, tender lymphadenopathy, hepatitis, and eosinophilia. We report a novel case of clinical hypersensitivity syndrome secondary to gabapentin. A patient developed altered mental status, fever, diffuse macular rash, and an enlarged spleen. This constellation of symptoms and signs began 9 days after gabapentin therapy was begun. Quick resolution was noted after gabapentin was discontinued. To our knowledge, there are no reports of hypersensitivity syndrome to gabapentin.