Purpose of reviewThe purpose of this review is to present developments in cardiopulmonary bypass circuitry, and to give the authors' opinions on the causes of the potentially harmful processes that are initiated by cardiopulmonary bypass, and how they may be attenuated.Recent findingsMuch of the recently published work investigates the effect of various forms of biocompatible circuitry, either heparin bonded, or polymer coated. The increasing number of patients having off-pump coronary surgery allows comparison of such patients with those that have had surgery using the various forms of cardiopulmonary bypass circuitry.SummaryRecent developments of biocompatible circuits are promising in terms of their potential for reducing the perioperative inflammatory response. The use of such circuitry, however, is likely to be of benefit only when included as part of an overall strategy to control triggers of the inflammatory response during and after cardiac surgery, particularly in the high-risk patient.