Renal dysfunction is a serious complication after coronary artery bypass surgery with cardiopulmonary bypass. Cardiopulmonary bypass-related non-pulsatile flow, hypothermia, haemolysis, systemic inflammatory reactions and emboli are mentioned as possible causes for this postoperative renal dysfunction. In an attempt to avoid these deleterious effects of cardiopulmonary bypass, off-pump coronary artery bypass surgery has been rediscovered. Resurgence of interest in off-pump coronary artery bypass surgery is associated with the expectation that avoiding deleterious effects of the cardiopulmonary bypass leads to better outcomes and possibly decreased costs and resource use. We are currently practising in an era of evidence-based medicine that mandates the prospective randomized controlled trial as the most accurate tool for determining a treatment benefit compared with a control population. The present review article attempts to evaluate the current best available evidence from randomized controlled trials on the impact of off-pump coronary artery bypass surgery on postoperative renal dysfunction.