The pancreatic pseudocyst as a sequela of pancreatitis or pancreatic trauma can occur at any site in the abdomen. Its detection seems to be increasing with modern imaging tools such as abdominal ultrasound or abdominal CT scanning. But recently, we experienced a case of a pseudocyst due to a ruptured pancreatic pseudocyst which was misdiagnosed as a simple hepatic cyst by abdominal ultrasonography or abdominal CT scan. A 12-year-old male presented with recurrent epigastric pain during the past 4 years. On the abdominal ultrasound and abdominal CT scan, there was an 8x7.5 cm sized sharply defined thin-walled cyst in the left lobe of the liver. First, percutaneous (cather) drainage guided by ultrasonography was done. An exploratory laparotomy was performed because of signs of hemoperitoneum. A 8x7.5 cm sized cyst was found at the left subhepatic space, which communicated with another smaller cystic lesion in the pancreatic head. Microscopic finding of the cyst showed infiltration of inflammatory cells and granulation tissue without ephithelial lined cells which is compatible to a pseudocyst. So we report this case with a review of literatures.