Nocardiosis arose in seven of 191 liver transplant patients (3.7%) over a period of 3.5 years. Four patients had only pulmonary lesions while three had disseminated disease. Nocardia asteroides was isolated from three patients following bronchoscopy, percutaneous aspirate of a pulmonary lesion in one patients, and from the skin from the aspirates in three patients. Delay in diagnosis in two cases was due to negative microscopy; in one, the diagnosis was made only after repeated bronchoscopy. Of the seven patients, three (43%) died. In two of these, nocardiosis was considered to have directly contributed to death. Co-existent bacterial and viral infections were present in all patients who died. In vitro susceptibility of the organism to co-trimoxazole was variable and did not necessarily reflect clinical efficacy. In one patient, a good clinical response was achieved with co-trimoxazole despite apparently reduced in vitro susceptibility.