Background: Primary squamous cell carcinoma(SCC) of the kidney is a rare malignancy, associated with nephrolithiasis, chronic irritation and infection. Because there are no specific clinical symptoms or test characteristics, it is difficult to diagnose through preoperative examination. It is confirmed by pathologic findings after nephrectomy. We report a case of primary SCC in the kidney. Methods: A 59-year-old man was referred from a clinic because of gross hematuria for a week. He had diabetes mellitus and hypertension, but no history of renal calculi and urinary tract infection. Results: In the urinalysis, there was 1+protein, WBC 15~20/HPF(0-3/HFP) and RBC many/HPF(0-3/HFP). In the urine culture, no bacteria were grown. His renal function was normal. Non-contrast abdominal CT showed multiple renal stones and a mass-like lesion in the right kidney. To further evaluate a mass-like lesion, contrast abdominal CT was performed , which demonstrated 6 cm, heterogeneous mass like lesion and suspected renal cell carcinoma. A nephrectomy was performed. Macroscopically, the specimen consisted of a right kidney, measuring 16×10×8.5cm and 620g. On section, the cut surface revealed a large irregular solid and necrotic, gray-white, mass, with granular appearance(8x7cm), filling up the mid pelvis and calyceal system with renal stones. The lower, dilated pelvicalyceal system is filled with multiple, small, yellowish green, round to polygonal shaped stones. Microscopic examination demonstrated moderately differentiated squamous cell carcinoma of renal pelvis with frequent tumor necrosis and multiple renal stones. There was extensively infiltrating the renal parenchyma, focally invading the perinephric fat tissue(pT4), and vascular tumor emboli in the perinephric fat tissue. No tumors were found in the margin of vascular and ureteral resection. There were no identifiable lymph nodes for assessment. Conculsions: In the analysis, calcium oxalate monohydrate stone was identified. On the chest CT, an enhanced nodule was identified and suspected metastasis. He transferred to oncology for chemotherapy.