A morbidity obese woman took a touring holiday which included two long flights and a stay at altitude. At the end of the second week of her holiday she was admitted to hospital in respiratory and cardiac failure. When she was better she travelled home by a combination of air ambulance and scheduled flights with a medical escort. This extreme case illustrates some of the physiological and physical challenges of air travel to the obese passenger, which may precipitate respiratory and cardiac decompensation in susceptible individuals. When advising these patients, consultation with the airline medical department is recommended, and preflight testing by altitude simulation may be helpful. If medical transport is required, there may be particular problems in lifting and accommodating these patients on board normal air ambulance aircraft.