Herein we present the F-FDG PET/CT findings in conjunctival melanoma as a second primary cancer in a 56-year-old Taiwanese man with a history of small lymphocytic lymphoma/chronic lymphocytic leukemia and nasal cavity carcinoma under remission. The right eye lesion slowly progressed since noted by the patient himself 2 years ago, but he refused biopsy and further treatment including surgery. Either small lymphocytic lymphoma/chronic lymphocytic leukemia or conjunctival melanoma is extremely rare in Asians, left alone in combination with a third malignancy of nasal cavity carcinoma. FDG PET/CT could effectively evaluate malignancies with multiple primary origins.