Acute cyanide poisoning by ingestion is often severe and lethal among jewellery industry workers. Clinical experience with hydroxocobalamin alone in severe acute cyanide poisoning by ingestion remains limited. This case concerns a 50-year-old goldsmith who tried suicide by ingestion of a jewellery cleaner solution containing approximately 1.2 g of potassium cyanide. He presented unconsciousness, with severe lactic acidosis and arteriolisation of venous blood gases. Following hydroxocobalamin treatment, neurologic and metabolic disorders rapidly improved. He was discharged home 4 days later, without neurological sequelae. The case reinforces the safety and effectiveness of hydroxocobalamin in acute cyanide poisoning by ingestion.