Dangerous misuse of anaesthetic drugs is illustrated in a case of gamma-hydroxybutyrate (gamma-OH) poisoning. A 36-year-old patient, coming from USA ingested approximately 200 mL of a liquid. He presented a non reactive coma (Glasgow coma scale at 3), abnormal movements, hypotension and bradycardia. Outcome was favorable with symptomatic treatment including tracheal intubation and ventilation. The patient was discharged 24 hours later. This case was a typical gamma OH poisoning. Its consumption is current in the United States for body-builders. Poisoning was involuntary, due to a dilution mistake. Toxicological analysis assessed this diagnostic. Such poisoning is exceptional in France.