A best evidence topic was written according to a structured protocol. The question addressed was whether on-pump beating heart coronary artery bypass (BH-ONCAB) surgery has a different outcome profile in comparison to off-pump coronary artery bypass (OPCAB). A total of 205 papers were found by systematic search of which 7 provided the largest and most recent outcome analysis comparing BH-ONCAB with OPCAB, and represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results were tabulated. Reported outcome measures included mortality, stroke, myocardial infarction, renal failure, myocardial damage, change in ejection fraction, number of bypass grafts and completeness of revascularization. With the exception of one study that favoured the off-pump technique, our review did not demonstrate a statistically significant difference in terms of mortality between the groups. We did not identify a statistically significant difference in any reported morbidity outcomes. However, there was a trend towards better outcomes for the on-pump beating heart technique, despite a higher risk profile in terms of age, ejection fraction and burden of coronary disease in this group. Consistent statistically significant differences between the groups were the mean number of grafts performed and the completeness of revascularization, both of which were higher with the on-pump beating heart technique. Limitations to the current evidence include the finding that most of the current data arise from specialist off-pump surgeons or centres that would usually only carry out BH-ONCAB in the higher risk patients where the added safety of cardiopulmonary bypass is desired.