Primary adenocarcinoma of the bladder is a rare neoplasm comprising less than 2% of all bladder tumors. Approximately one-third of primary bladder adenocarcinoma arise in the urachal remnant. Differentiation from vesical adenocarcinoma preoperatively is essential because the surgical approach differs. We herein present a case of urachal adenocarcinoma whose radiographic work-up permitted the correct preoperative diagnosis.