A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether radial arterial harvest with a harmonic scalpel produced a lower incidence of complications or was superior to conventional harvest with the diathermy or scissors and clip techniques. Two hundred and forty-seven papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses were tabulated. We identified 10 studies, 2/5 studies report faster harvesting with the harmonic scalpel, 6 studies report reduced requirement for surgical clips, 2 papers report less spasm, 2/4 studies reported less numbness, and 2 studies reported no electron microscopic differences. Three studies looked at angiography or flow, with one equivocal, one in favour of harmonic and one in favour of scissors and clips. We conclude that there is little convincing evidence in the literature to guide the decision to use a harmonic scalpel over electrocautery for radial artery harvest.