A fifteen-year-old girl, with a clean medical history, was admitted to the intensive care unit 90 minutes after ingestion of 2.5 g potassium cyanide. She had typical signs of severe cyanide poisoning including deep coma, circulatory failure, and major metabolic acidosis. Gastric lavage and antidotal treatment with 4 g hydroxocobalamin and 8 g sodium hyposulfite was administered without delay together with supportive treatment consisting of mechanical ventilation with FIO2, blood alkalinisation and administration of beta-stimulants. These measures led to a rapid clinical improvement. The ventilatory support was discontinued after 24 hours and the patient left the intensive care unit on the fourth day with only slightly impaired mental status. She survived despite a very high blood cyanide concentration (494 mumol.l-1 on admission) probably because of the rapid symptomatic and antidotal treatment.