Objective To investigate causes of escape diagnosis of renal pelvis carcinoma with non-functioning kidney due to renal calculi. MethodsFrom June 2014 to June 2019, 4 cases of renal calculi with nonfunctioning kidney combined with renal pelvis cancer in our hospital were selected as the research objects, including 3 males and 1 female, aged 70-78 years, with a history of 11-16 years. All of the 4 patients had low back pain, hematuria and urinary tract infection,of which 2 patients had fever. No renal pelvis cancer was found by intravenous urography, color Doppler ultrasound and CT. One patient complicated with lower ureteral calculi and bladder calculi underwent nephroureterectomy and cystolithotomy, and the other three underwent simple nephrectomy.Results Postoperative pathological examination revealed-1 case of primary renal pelvic adenocarcinoma, 2 cases of urothelial carcinoma and 1 case of squamous cell carcinoma. All patients were followed up, 1 case died of tumor recurrence and metastasis after half a year, 1 case lost to follow-up after half a year, 1 case had no tumor recurrence after 4.5 years of follo-up, 1 case had no tumor recurrence after 1.5 years of follow-up. Conclusion It was easily to neglect the diagnosis of renal pelvis carcinoma due to non-specificity in clinical manifestations and imaging examinations. A diagnosis of renal pelvis carcinoma should be considered in a patient with aged, long-term renal calculi complicated with severe hydronephrosis and infection. Then, further examinations should be done. In addition, the specimens should be examined carefully during the operation.