This study aimed at investigating the thermal welding (TW), classic dissection (CD) and bipolar cautery dissection (BCD) tonsillectomy in adults. 120 adults with chronic tonsillitis, who were scheduled for elective tonsillectomy between January 2009 and April 2012, were randomized to tonsillectomy with the TW, CD and BCD methods. Operation time, intraoperative blood loss, post-operative haemorrhage rate and especially post-operative pain were evaluated. The difference between operative time of the TW and BCD groups against CD group was statistically significant (p < 0.05). The difference between intraoperative blood loss of the TW and BCD groups against CD group was statistically significant (p < 0.05). No significant difference was found in the incidence of post-tonsillectomy haemorrhage between the three groups (p > 0.05). The difference between post-operative pain score between CD and TW was not statistically significant (p > 0.05). The difference between post-operative pain score of the two groups against BCD group was statistically significant (p < 0.05). TW technique is a relatively safe and reliable method with significantly less post-operative morbidity than CD and BCD tonsillectomy. When we compared TW with the CD and BCD tonsillectomy, we found significant reduction in the surgical time and the intraoperative blood loss without any increase in the post-operative pain.