The abdominal compartment syndrome (ACS) is a newly appreciated and potentially fatal consequence of increased intra-abdominal pressure. It can be due to either trauma or surgery, as well as numerous medical conditions. Prolonged, unrelieved elevation of intra-abdominal pressure can produce pulmonary compromise, renal impairment, cardiac failure, shock, and death. A high index of suspicion is imperative. Measurement of the intravesical pressure provides a urometric window for detecting and monitoring this condition. Reopening the abdominal incision (decompressive celiotomy) has proven a life-saving intervention. Use of delayed wound closure (staged celiotomy) may prevent development of this condition in high-risk surgical patients. It is urgent that all physicians, and surgeons in particular, be alerted to this potentially lethal complication.