Purpose: Introduction: Non-metastatic hepatic dysfunction in patients with renal cell carcinoma (RCC) is known as Stauffer's syndrome. It is thought to be one of the paraneoplastic manifestations of RCC. Stauffer's syndrome may precede typical manifestations of RCC. Therefore, unexplained elevated liver enzymes warrant an aggressive search for RCC. Case Presentation: A 75-yearold male with a history of dementia, diabetes mellitus, hypertension, and end stage renal disease on hemodialysis presented to the emergency department for 1 episode of coffee ground emesis. The emesis was preceded by nausea and epigastric pain. His vital signs were T 99.6 F, HR 91 /min, RR 18 /min, BP 130/75 mmHg, SpO2 97% on ambient air. His heart sounds were regular and lungs were clear to auscultation. His abdomen was soft, but mild epigastric tenderness was observed. His left arm AV graft site was intact. Labs were significant for T-Bil 1.5 mg/dL, D-Bil 1.1 mg/dL, ALP 297 U/L, AST 953 U/L, ALT 699 U/L, Amylase 114 U/L, Lipase 430 U/L, LDH 3573 U/L, BUN 72.0 mg/dL, Cr 4.4 mg/dL, K 5.3 mmoL/L, WBC 11.7 K/μL, HGB 12.8 g/dL, PLT 116 K/μL. Hepatitis panel was negative. Abdominal/pelvic CT revealed two large heterogeneous solid lesions originating from the upper to mid pole of the right kidney. The larger right renal mass measured approximately 9.7 x 7.7 cm in axial dimension and was partially calcified. The smaller right renal mass demonstrated a claw sign with the midpole of the kidney and measured approximately 6.3 x 4.3 cm. The gallbladder was intact without stones. The liver was normal in size and contour with homogenous enhancement. There was no intrahepatic or extrahepatic bile duct dilatation. No metastasis was found. Because of the patient's poor functional status, surgery was not considered and he was treated conservatively. Discussion: RCC is associated with a wide variety of paraneoplastic syndromes. Since they can be an initial presentation of RCC, recognition is particularly important to make an early diagnosis and facilitate treatment. Stauffer's syndrome is an uncommon form of paraneoplastic syndrome, which makes diagnosis difficult for clinicians. As shown in our case, RCC is often found incidentally. The hepatic dysfunction is thought to result from the production of cytokines from the tumor. The differential diagnoses from hepatic metastasis, bile duct obstruction, or other causes of elevated liver enzymes are of clinical important. However, patients with unexplained liver enzymes should be suspected for Stauffer's syndrome and investigated for RCC.