Patients with a long-term history of inflammatory bowel diseases show an increased risk of developing colorectal cancers. In the case of Crohn's disease, such an increased risk is also associated with other malignant tumors. The report presents a very rare case of a concomitant carcinoid tumor and papillary urothelial neoplasm of low malignant potential in a 35-year-old patient with diagnosed Crohn's disease complicated by an enterovesical fistula. The carcinoid tumor and papillary urothelial neoplasm of low malignant potential were diagnosed by postoperative histopathology. In patients with Crohn's disease, concomitant occurrence of various malignancies may be observed even earlier in life.