Small cell neuroendocrine carcinoma (SCNEC) of the ureter is extremely rare, and tends to show a mixed histologic profile. Literature on its imaging features is limited.We herein report the case of a 68-year-old woman who presented with two days of left flank pain. Ultrasound and CT scan revealed a lesion in the left distal ureter. The lesion exhibited intensive tracer activity on 18F-FDG PET/CT scan, corresponding to a malignant tumor, most likely a high-grade urothelial carcinoma, and no metastases were observed. Then, the patient underwent a radical left nephroureterectomy. Pathology revealed a carcinoma composed of SCNEC (approximately 83%) and urothelial carcinoma (approximately 17%). During one year of follow-up, the patient underwent six cycles of adjuvant chemotherapy (etoposide 100mgd 1-3 + cisplatin 30mgd 1-3, q3w), and no recurrence or metastases were found on the CT scan.This case report has presented a case of ureteral SCNEC and explored the value of 18F-FDG PET/CT in the diagnosis and staging of the disease.Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.