A 29-year-old chemistry student took 50 ml of a 1% potassium cyanide solution (500 mg) in an attempted suicide. He became comatose, mydriatic, and was admitted to hospital in an apneic state. He woke up after 7 h and developed Parkinsonism in the following weeks. This regressed slowly during the 2 months after the poisoning apart from dysarthria, bradykinesia of the upper limbs, and very brisk monosynaptic reflexes. At 3 weeks after the intoxication, computerized tomography was largely normal, and there was CSF-dense hypodensity in both putamina after 5 months. Sharply delimited signal elevation in T2 corresponding to the two putamina was detected by magnetic resonance imaging 8 weeks and 5 months after ingestion of the poison.