en Surgery Surgery case report case report Various complications of hydatid cyst have been recognized to date. We have encountered one such complication-rupture of hydatid cyst to the duodenum­ leading to upper gastrointestinal bleeding in a 40 year old male, who referred with severe right upper quadrant (RUQ) pain and gastrointestinal bleeding of a few hours' duration. Laparotomy revealed a cyst (7 x 15 cm) in the left lobe of the liver which was adherent to the duodenum and mesocolon. To the best of our knowledge, this is the first report of gastrointestinal bleeding resulting from hydatid cyst rupture into the duodenum. Echinococcosis, Compl ications, Gastrointestinal bleeding, Duodenal rupture 373 374 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-344&slc_lang=en&sid=1 H SALAHI 20031947532846005038 20031947532846005038 Yes From the Department of Surgery, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran