Eighty-eight episodes of MRSA septicaemia occurring in 82 patients were studied prospectively. In 15 episodes bacteraemia was transient, in 36 non-fatal, in 33 fatal, while in four septicaemia was a major contributory factor in the patient's death. There were more patients aged over 60 years in the septicaemia groups compared to the transient bacteraemia group (P = 0.01), and patients with septicaemia were usually recently postoperative and/or suffering from severe underlying disease. Circulation access sites were the commonest source of the bacteraemic organisms with non-surgical wounds including burns, varicose ulcers and bed sores as the next most common. In four of the 16 burns patients, fatal septicaemia followed surgical debridement of infected burns. In only eight episodes was there no apparent source of bacteraemia.