Meckel's diverticulum is an uncommon gastrointestinal congenital anomaly that occurs in 1-3% of the population. It is sometimes associated with complications related to the presence of ectopic tissue (obstruction, ulceration, hemmorhage, inflammation, perforation, fistula and tumors). Neoplastic degeneration of Meckel's diverticulum mucosa is rare, developing in only 1-5% of all diverticula, usually asymptomatic and occasionally discovered. Disease is metastatic, usually to the liver, in 25% of cases. We report a case of asymptomatic unsuspected carcinoid of Meckel's diverticulum with ileal, hepatic and mesenteric metastasis discovered during a gastrectomy performed for gastric adenocarcinoma. The patient underwent ileal and Meckel diverticulum resection, excision of mesenterial metastasis and liver bisegmentectomy. Furthermore, total gastrectomy with esophago-jejunal anastomosis was performed. After an 18-month follow-up period, the patient is alive and disease free. Owing to possible neoplastic degeneration, Meckel's diverticulum should be resected when occasionally discovered. In the presence of a carcinoid tumor, even if associated with metastatic disease, extended resection is recommended.