• RFCTB had a higher rate of success than HTP in treating moderate to severe OSA in adults. • In cases of Hypopharyngeal level obstruction, both HTP and RFCTB were able to improve OSA completely. • In cases of multiple levels obstruction, both HTP and RFCTB were able to improve OSA to less degrees according to the severity of the preoperative parameters . • Although planning the procedures used in this study didn’t depend on the finding of Fiber-optic Nasal Endoscopy with Müller's Maneuver (FNMM) or Drug-induced Sleep Endoscopy Method (DISE) , the results are comparable to those of other studies that following DISE classification in choosing the operative procedure. • Limitations of this study are the relatively small number of the included patients and its short time of follow up.