Sarcomatoid carcinoma of the renal pelvis accounts for a very low percentage of malignant tumors in the renal pelvis and has a poor prognosis. This article reported a patient with sarcomatoid carcinoma of the renal pelvis. The patient presented with macroscopic hematuria as the first symptom, and CT suggested left renal occupancy, unilateral nephrectomy was performed, and pathology suggested sarcomatoid carcinoma of the renal pelvis. Three weeks after surgery, a follow-up CT showed tumor recurrence. Programmed death 1(PD-1)inhibitor was given once every 3 weeks. Repeated CT examination after 24 weeks of continuous treatment suggested that the recurrent tumor disappeared. The patients was followed-up for 42 months without tumor recurrence or metastasis.