Human uterine transplantation was performed on 6 April 2000 on a 26-year-old female who lost her uterus 6 years earlier due to post-partum hemorrhage. The donor, a 46-year-old patient with multiloculated ovarian cysts, underwent a hysterectomy modified to preserve tissue and vascular integrity. The donor uterus was connected in the orthotopic position to the recipient's vaginal vault and additional fixation was achieved by shortening the uterosacral ligament. The uterine arteries and veins were extended using reversed segments of the great saphenous vein, then connected to the external iliac arteries and veins, respectively. Immunosuppression was maintained by oral cyclosporine A (4 mg/kg/body wt.), azathioprine (1 mg/kg/body wt.) and prednisolone (0.2 mg/kg/body wt.). Allograft rejection was monitored by Echo-Doppler studies, magnetic resonance imaging (MRI), and measurement of the CD4/CD8 ratio in peripheral blood by fluorescence activated cell sorter (FACS scan). An episode of acute rejection was treated and controlled on the ninth day with anti-thymocytic globulin (ATG). The transplanted uterus responded well to combined estrogen--progesterone therapy, with endometrial proliferation up to 18 mm. The patient had two episodes of withdrawal bleeding upon cessation of the hormonal therapy. Unfortunately, she developed acute vascular thrombosis 99 days after transplantation, and hysterectomy was necessary. Macro- and microscopic histopathological examination revealed acute thrombosis in the vessels of the uterine body, with resulting infarction. Both fallopian tubes remained viable, however, with no evidence of rejection. The acute vascular occlusion appeared to be caused by inadequate uterine structure support, which led to probable tension, torsion, or kinking of the connected vascular uterine grafts.