On Feb. 3, 1975, 196 (57%) of 344 passengers and 1 steward aboard a commercial aircraft contracted a gastrointestinal illness characterised by nausea, vomiting, abdominal cramps, and diarrhoea; 142 passengers and the steward were admitted to hospital. Symptoms developed shortly after a ham and omelette breakfast had been served. An investigation strongly incriminated ham as the vehicle of the outbreak, and the source seems to have been a cook with lesions on his fingers. The attack-rate was 86% for passengers who ate the ham handled by this cook and 0% for passengers who ate ham handled exclusively by another food preparer. Before being served, the ham and omelette had been held at room temperature for 14 h and at 10 degrees C (50 degrees F) for 14 1/2 h Specimens of stool and vomitus from ill passengers, left-over food, and the finger lesions of the cook were positive for Staphylococcus aureus of identical phage types and antibiotic sensitivities. Preformed enterotoxin was detected in the left-over ham and omelette. This outbreak re-emphasises that people with infected lesion should not handle food and that foods must be stored at temperatures low enough to inhibit the growth of bacteria. To ensure against a common foodborne illness incapacitating the entire flight crew, cockpit crew members should eat different meals prepared by different cooks.