Among organ transplant recipients there is a world wide increase in the number of de novo tumors as well as a decrease in the time of the first appearance after the transplantation. Between 1973 and the 31st of August 1999 1709 cadaver renal allograft transplantations were performed in our Department. Four thyroid cancers were detected among the renal transplanted patients. Two of them proved to be papillary microcarcinomas. Although the elevated risk of thyroid cancers is well established in the literature papillary microcarcinomas have never been reported before in an immunosuppressed patient. Authors highlight that the thyroid gland should always be carefully checked in organ transplant recipients, since better survival might be achieved even in the immunosuppressed population. Metastatic tumor is relatively benign which is in correlation with the literature, but there has been little experience in organ transplanted patients so far.