In a 64-year-old man heart transplantation had been performed for ischaemic heart disease. 7 months later severe vascular disease in the transplant necessitated a second transplantation. Both procedures had been performed under immunosuppression (cyclosporine, azathioprine, prednisolone, antithymocyte globulin), with a subsequent prednisolone maintenance dose of 10 mg daily. At first there were no complications, but 31 days after the re-transplantation atrial flutter developed. Although this was quickly terminated by drugs, circulatory failure set in. Because of signs of infection (white blood cell count 29800/mu l, 17% stab cells, C-reactive protein 24 mg/l) broad-spectrum antibiotics were administered, but without response. As a trial anti-rejection treatment was started (prednisolone 250 mg daily: antithymocyte globulin 100 mg daily for 4 days). When cytomegalovirus (CMV) infection was demonstrated, ganciclovir and CMV hyperimmunoglobulin were administered and slow improvement was noted. The finding of Aspergillus in tracheal secretion was interpreted as apathogenic colonization. The patient died from cardiorespiratory failure 57 days after the second transplantation. Autopsy revealed Aspergillus sepsis.