The spectrum of infectious complications during the first six months after 101 consecutive renal transplants was examined. The most common sites of infection were the lungs, the urinary tract, and the surgical incision. The causative organisms were similar to those in nonimmunosuppressed postsurgical patients. The infections were usually recognized readily by routine clinical examination and responded promptly to antibacterial therapy. Three patients developed opportunistic infection. No patient died as a result of infection. As at several other institutions in recent years, a declining frequency of serious or opportunistic infection in these immunosuppressed patients was noted. However, the results of this study differed markedly from recently reported data which emphasize the importance of overt cytomegaloviral disease as a cause of morbidity and as a factor predisposing to serious--often fatal--superinfection. These differences may be related to the immunosuppressive agents used and certainly have important implications for diagnostic and therapeutic management.