Abdominal compartment syndrome (ACS) is a life.threatening disorder caused by rapidly increasing intra.abdominal pressure. ACS can result in multiorgan failure and carries a mortality of 60~70%. The treatment of choice in ACS is surgical decompression. There are very few reports of ACS and experience in Korea. We report 12.year.old male patient who developed an abdominal compartment syndrome due to traffic.accident.induced retroperitoneal hematomas, Which was successfully treated by performing a bedside emergency surgical decompression with open linea alba fasciotomy with intact peritoneum.