Solid organ transplantation provides life-saving therapy for patients with end-stage organ disease, and its outcomes have been improving dramatically over the past few decades. However, substantial morbidity results from chronic immunosuppressive therapy administered to prevent graft rejection. It predisposes patients to several life-threatening complications, such as opportunistic microbial infections and the development of different types of cancers. Here, we presented the case of a young man with probable Lynch syndrome, who developed an aggressive colon carcinoma after long-term immunosuppressive therapy due to a prior liver transplantation. Based on this case report, we attempt to find an answer to the question about the risk of cancer development or recurrence in patients with familial syndromes receiving long-term immunosuppressive therapy and to find out how it can be minimized. Answering these questions is particularly important, given the facts that disease course is substantially more aggressive among transplanted patients and that prognosis is poor due to lack of immunocompetence, especially in the setting of Lynch syndrome.