Mekkel's diverticulum (MD)--is the inborn anomaly, caused by incomplete yolk duct development, it is present in near 2% of population and in 95% of observations lacks clinical manifestations. Symptoms of the disease manifest while complications occurrence only--in presence of peptic ulcer with possible hemorrhage and perforation occurrence, while ileus, diverticulitis, hernia, umbilicus fistula and tumor development. Eight patients, suffering MD, complicated by gastrointestinal hemorrhage, were treated during 1983-2006 yrs in Kyiv's city center for giving the aid to patients suffering gastrointestinal hemorrhage (GIH). These had constituted 6.6% of general quantity of adult patients, suffering rare causes of GIH occurrence, and 0.03% of all the patients, suffering GIH. For the diagnosis establishing in all the patients colonoscopy, barium enema and abdominal ultrasonography were applied. Definitive diagnosis was established only postoperatively. MD was extirpated in 5 patients, the wedge ileum resection with MD was accomplished in 1 patient and ileum resection with MD--in 2 patients. All the patients are alive.