BACKGROUND Differences in graft survival due to gender have been reported after transplantation of the kidney, liver, and heart. However, little is known about the role of donor and recipient gender in simultaneous pancreas-kidney transplantation. METHODS Single-centre analysis was performed of first simultaneous pancreas-kidney transplantations performed between 1994 and 2005 at the Bochum Transplant Center in Germany (n=218). RESULTS Recipients of female donor organs exhibited acute organ rejections earlier and more frequently (P<0.05). Male recipients of organs from male donors had a lower risk of acute rejection than recipients of female donor organs (P<0.05). In addition to female donor gender, higher donor age and early kidney dysfunction were risk factors for perioperative rejection (P<0.05). Long-term kidney and pancreas function was best in male-donor-to-female-recipient transplants over the time periods of 7 and 3 years, respectively (P<0.05). Risk factors of long-term organ failure were: the need of revision laparotomy, organ rejection, and early postoperative organ dysfunction (P<0.05). CONCLUSIONS This is the first report of graft function after simultaneous pancreas-kidney transplantation looking specifically at gender differences with respect to donor and recipient. There was an increased risk of organ rejection of female donor organs.