Sarcomatoid transitional cell carcinoma is a rare malignant epithelial neoplasm arising at the bladder, in which the tumor cells assume a spindle shape. This tumor accounts for approximately 0.3% of all bladder malignancies and has been reported in the renal pelvis and ureter. We encountered a case of histopathologically proven sarcomatoid transitional cell carcinoma of the left kidney in a 76-year-old male. Abdominal CT scans showed a large heterogeneous mass of solid and cystic components, with mural calcification and hematoma in the upper pole of the left kidney.