The standard therapy for thyroid cancer is total or near total thyroidectomy, followed by the administration of radioactive iodine for remnant ablation or residual disease. Patients with radioiodine therapy are predisposed to second malignant neoplasms in organs such as central nervous system (CNS), breast, prostate, kidney, bone marrow, salivary gland, and digestive tract. Exposure to carcinogen including occupational and therapy related hazard, aging and genetic susceptibility are other causes of second primary cancers. The second primary malignancies are not uncommon and, nowadays, the prevalence of it is mildly increasing due to the increasing survival of cancer patients and advances in early diagnosis and therapeutic modalities. Here, we present a fifty-one-year-old man with papillary thyroid carcinoma (PTC), who developed chronic lymphocytic leukemia (CLL), renal cell carcinoma (RCC), and basal cell carcinoma (BCC) in 15-20 years after radioactive iodine therapy. Second primary tumors are increasing and environmental, genetic susceptibility and increase in survival of cancer patients are the major risk factors.