This study reports major gastrointestinal (GI) complications among a group of 1611 patients following kidney transplantation. The immunosuppressive regimen changed somewhat during the course of the study but included azathioprine, prednisolone, antilymphocyte globulin, cyclosporine, tacrolimus, mycophenolate mofetil, and sirolimus. Perforations occurred in the colon (n=21), small bowel (n=15), duodenum (n=6), and stomach (n=4). Nearly 50% of the complications occurred while patients were being given high-dose immunosuppression to manage either the early postoperative period or acute rejection episodes. Of the 46 patients affected, 11 (24%) died as a direct result of the GI complication. This high mortality appeared to be related to the effects of the immunosuppression and the associated response to sepsis. Reduction of these complications may be achieved by improved surgical management, preventive measures, prompt diagnosis, and a reduced immunosuppressive protocol.