We report a case of a sigmoid-urachal-vesical fistula associated with urothelial carcinoma that resulted from complications of an infected urachal remnant with a brief review of the most relevant clinical and radiological findings. The lesion presented as a supravesical enhancing mass that communicated with the sigmoid colon. In this case, the lesion was suggestive of malignant transformation of the infected urachal diverticulum in an adult male. Radiological findings are Considered as helpful for the preoperative diagnosis and proper management of unusual complications of an urachal remnant.