We undertook a study of the characteristics and clinical impact of infections due to methicillin-resistant Staphylococcus aureus (MRSA) after liver transplantation. Of 165 patients who received liver transplants at our institution from 1990 through 1998, 38 (23%) developed MRSA infections. The predominant sources of infection were vascular catheters (39%; n = 15), wound (189 ; n = 7), abdomen (18%; n = 7), and lung C13%; n = 5), A significant increase in MRSA infections las a percentage of transplant patients infected per year) occurred over time (P = .0001), This increase was greater among intensive care unit patients (P = .001) than among nonintensive care unit hospital patients CP = .17). Cytomegalovirus seronegativity (P = .01) and primary cytomegalovirus infection were significantly associated with MRSA infections (P = .005). Thirty-day mortality among patients with MRSA infections was 21% (8/38). Mortality was 86% in patients with bacteremic MRSA pneumonia or abdominal infection and 6% in those with catheter-related bacteremia (P = .004). Thus the incidence of MRSA infection has increased exponentially among our liver transplant recipients since 1990. These infections have unique risk factors, time of onset, and a significant difference in site-specific mortality; deep-seated bacteremic infections, in particular, portend a grave outcome.