INTRODUCTION: The cystic tumor of the pancreas is a relatively uncommon entity. There are different types of pancreatic cystic tumors and they all exhibit different degrees of malignancy. These tumors represent 1% of all primary pancreatic tumors and only 15% of the cystic lesions. The serous cystadenomas (SCA) are mostly benign lesions with an average size of 4 cm; nevertheless, in some rare cases these are giant lesions, generally larger than 15 cm. Sometimes these tumors produce a symptomatology caused by the compression of neighboring structures, therefore they are generally operable. MATERIAL AND METHOD: During the period from June 2004 to June 2005, the 3A II unit of the Edgardo Rebagliati Martins Hospital operated on two cases of giant serous cystadenomas of the pancreas, one located in the tail of the pancreas and the other in the head of the pancreas, with an average size of 16 cm. DISCUSSION: The giant SCAs of the pancreas are rarely seen lesions that, according to different authors, are usually larger than 10 to 15 cm. in diameter. These lesions do not represent a diagnosis problem and are generally operable since they produce a symptomatology by compression. The surgical resection can be complicated due to their large size and to the considerable neovascularization.