CONCLUSIONS Ligasure tonsillectomies took longer than bipolar diathermy scissors tonsillectomies. Peroperative haemostasis was comparable in the two groups. Postoperative haemorrhage was higher than expected, which needs to be further investigated. A new handpiece, specifically designed for tonsillectomy, could probably improve surgical performance regarding operative time. OBJECTIVE To compare tonsillectomy using Ligasure with bipolar diathermy scissors with regard to operative time, blood loss and complications. METHODS This was a prospective study; 150 patients (> 15 years of age) undergoing tonsillectomy were randomized to tonsillectomy using either Ligasure or bipolar diathermy scissors. Operative time, peroperative blood loss, postoperative pain and complications were recorded and evaluated. RESULTS A total of 149 cases were included, 75 randomized to Ligasure tonsillectomy and 74 to bipolar diathermy scissors tonsillectomy. Peroperative blood loss was similar in both groups. On average the operative time was 8 min longer in the Ligasure group. Postoperative pain was similar in the two groups. Twenty patients (13%) experienced postoperative haemorrhage, which is higher than our previous material. Slightly fewer patients experienced postoperative haemorrhage in the Ligasure group compared with the diathermy scissors group but the difference was not significant. Two of the 20 patients that experienced postoperative haemorrhage required a return to theatre to stop the bleeding, fewer than previously observed. No other complications were seen.