Radiofrequency surgery was introduced to minimize thermal damage to the tissue. A radiofrequency electrode can be used to make cuts in the free edge of the soft palate like those done in laser-assisted uvulopalatoplasty [radiofrequency-assisted uvulopalatoplasty (RAUP)]. Tonsillectomy can enlarge the lateral diameter of the pharynx. The aim of our study was to evaluate the efficacy of RAUP with tonsillectomy in treatment of obstructive sleep apnea syndrome (OSAS). Ninety-two patients with obstructive sleep apnea were included in this study. Patients were categorized according to disease severity and Friedman's staging system. Patients were assessed with the preoperative visual analog scale (VAS) for snoring, Epworth Sleepiness Scale (ESS) and apnea-hypopnea index (AHI) at baseline and repeated at 6 months postoperatively. The intensity of postoperative pain, speech deficits and dysphagia were also recorded. There was a significant improvement in the VAS score for snoring, ESS and AHI before and after surgery. Overall, the results of the present study indicated a surgery success rate (a 50 % decrease in AHI and AHI <20) of 66 % (61 of 92 patients). Postoperative pain, speech deficits and dysphagia were reduced at 2 weeks after surgery. The results of this study suggest that RAUP with tonsillectomy is an effective treatment for patients with OSAS.