Between 1980 and 1989, 32 cases of invasive aspergillosis were identified out of 2315 consecutive necropsies, an incidence of 1.4%. The incidence in immunosuppressed "high risk" patients was 10.7%. Twenty out of 32 cases showed spread beyond the lungs, with the brain the most common site. There was an increase in cases in the second half of the decade, attributable to the start of a liver transplantation programme. Liver transplant recipients and patients with haematological malignancies were at significantly greater risk of acquiring aspergillosis than kidney transplant recipients or those with solid malignancies treated with chemotherapy. There was also a greater risk of haematogenous dissemination in liver transplant recipients than in all other groups, and this was significantly associated with the use of high dose steroids as anti-rejection treatment. Aspergillus was isolated during life in only eight cases, which indicates a continuing need for and emphasises the value of necropsy.