We present a case of synchronous bilateral renal cell carcinoma and prostate carcinoma in a 62 year old man. In a fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET) scan, the left renal mass showed intense 18F-FDG uptake with maximum standardized uptake volume (SUVmax) of 8.12, while uptake in the right renal mass was minimal with SUVmax of 2.99. Fluorine-18-FDG uptake in the prostate gland lesion was moderate with SUVmax of 4.19. Histopathologically, both renal tumors were clear cell renal cell carcinoma with International Society of Urological Pathology (ISUP) Grade 2 and 3 for the right and left kidney, respectively and prostate gland lesion was typical prostate gland carcinoma.