An elevated intra-abdominal pressure (IAP) above 12 mmHg is a pathological finding in critically ill patients. IAP are classified into different degrees of intra-abdominal hypertension and, in the presence of associated organ failure, as abdominal compartment syndrome. Both disease entities represent an underestimated factor in intensive care patients and are associated with increased mortality and prolonged intensive care and hospital stay. The measurement of intra-abdominal pressure in critically ill patients in intensive care units is not widely established and there is often considerable uncertainty regarding measurement conditions and methods. If risk factors are present, intra-abdominal pressure should be monitored every 4 hours. Bladder pressure measurement is the gold standard for determining intra-abdominal pressure. The measurement is a non-invasive, cost-effective, easy to perform bedside and safe method for the patient.