Four patients are described in whom massive abdominal distension after laparotomy led to increased airway and central venous pressure and severely reduced urine output. All cases were associated with massive fluid resuscitation and operative findings were a grossly oedematous bowel with free fluid under pressure in the abdomen. These findings are consistent with the diagnosis of intra-abdominal compartment syndrome. In 1 case trauma was remote from the abdomen indicating that abdominal surgery or trauma may not be a prerequisite for the development of the condition. Recognition of the features of the condition is essential as it can only be treated by decompression of the abdominal contents