The paper reports the case of a 53-year-old man admitted to hospital with melena. The initial diagnosis was bleeding duodenal ulcer; after 8 weeks of therapy the duodenal ulcer was completely healed, but renewed intestinal bleeding occurred three months later. Angiography of the upper mesenteric artery revealed a clear tumour form. A tumour of the small intestine the size of a fist was found during surgery. An ileal resection was performed. Histopathological tests confirmed the diagnosis of leiomyoma of the small intestine.