Heterotopic pancreas (HP) is defraed as abnormally localized pancreatic tissue without any anatomical and vascular connection with pancreas. Incidence of HP is 0.2-0.5% of patients underwent upper medial laparotomy. The most common symptoms of HP are abdominal discomfort and pain, upper gastrointestinal bleeding and intermittent bowel obstruction. Gastroscopy is the most commonly used first diagnostic procedure. Ultrasound evaluation, computer tomography and namely endoscopic ultrasound evaluation are useful imaging procedures of HP. Casuistic report of patient with upper gastrointestinal bleeding is presented. Imaging procedures have recorded stomach tumor 3cm in diameter in back wall of stomach. Billroth II resection of stomach was performed. Histological evaluation of removed part of stomach recorded heterotopic pancreas type 1 of Heinrich classification. HP diagnosis before surgery is difficult because of submucous localization of lesion. Fine needle biopsy during gastroscopy is one of diagnostic possibilities without surgery. Endoscopic excision of lesion is possible if histological evaluation by fine needle biopsy is successful and anatomical localization is appropriate. The most of patients need surgical excision of HP. Peroperative histological evaluation allows a minimalization of excision area. Opinions of asymptomatic HP treatment are ambiguous. The most of published papers recommend excision of asymptomatic HP also, because of risk of next complications.