A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Should you place one or two chest drains in patients undergoing lobectomy?' Altogether >200 papers were found using the reported search, of which six represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that the insertion of one chest drain confers less postoperative pain as shown by one randomised controlled trial (RCT) and one further cohort study. In addition, another RCT was able to demonstrate a lower use of non-standard analgesia in the face of no overall difference in total pain score while another RCT conveyed a significantly shorter duration of opioid and NSAID use inferring less postoperative pain. From all the studies in this area, no differences in the duration and amount of drainage or the length of hospital stay could be demonstrated with any significance. Therefore, the use of the conventional two drain method is not superior to the one drain method and may indeed cause more pain and is obviously more expensive.