From March 1972 to 1st of January 1996, 804 kidney, liver and pancreas transplants were performed in 690 patients. 39 post transplant cancers occurred in 27 patients. 21 skin tumors (15 squamous cell carcinoma, 4 basocellular carcinomas, 1 squamous carcinoma, 1 melanoma), 4 squamous cancers (anus, esophagus, tongue, and parotid), 4 post-transplant lymphoproliferative disorders, 1 non-Hodgkin's lymphoma T, 4 gynecological tumors (breast, ovarian peritoneal carcinomatosis, 2 uterine cervix cancers), 4 miscellaneous tumors (larynx, right colon, brain, prostate, own kidney). 14 patients died (14/27: 52%). Post transplant de novo cancers are a major risk in transplant patients These cancers are mainly represented by skin tumors and lymphomas. Skin cancers are mainly spinocellular and occur in the areas which are exposed to the sun. Post transplant lymphoproliferative disorders are very close to Burkitt's lymphoma, they produced B lymphocyte proliferation due to the reduction of the control of T lymphocytes and induced by Epstein-Barr virus. They can disappear with the diminution of immunosuppression.