Summary Perioperative complications contribute significantly to the morbidity and mortality of surgical procedures. Although the aetiology and pathophysiology of perioperative complications are complex, reduced cardiopulmonary reserve appears to play a major role. In recent years, inadequate oxygen delivery and the resulting oxygen debt of organs have been shown to be a leading cause of perioperative complications. Accordingly, perioperative monitoring of the cardiovascular system has a considerable impact on outcome. There is general agreement on the necessary safety monitoring that is to be used in every patient undergoing anaesthesia or intensive care therapy. Such minimal safety monitoring comprises an ECG, non-invasive blood pressure measurements, pulse oxymetry and (in ventilated patients) capnography. In contrast, it remains largely unknown whether – and if so, which – patients benefit from advanced haemodynamic monitoring in the form of cardiac output measurements, venous oxymetry and the estimation of cardiac pre- and afterload. In the present review, we describe the specific characteristics of currently available haemodynamic monitoring tools, and attempt an assessment of their clinical value.