Aim: Investigate the surgical outcomes of a uvulopalatal flap (UPF) in the treatment of patients with mild and moderate obstructive sleep apnea (OSA). Materials and methods: In our study we have evaluated the success rate of uvulopalatoplasty procedure in 13 patients by performing preoperative and postoperative polysomnography and nasopharyngoscopy (NFS). We used flexible scopes under propophol sedation for nasopharyngoscopic evaluation in our in-house patients. Two of the patients were not evaluated by preoperative nasopharyngoscopy because they had been operated in another centre. In all other patients in whom preoperative nasopharyngoscopy had been performed in our clinic, a retropalatal obstruction was diagnosed. Findings: Median age was 39 (range: 23-67). Preoperative apnea hipopnea indices (AHI) was 22.3/h (range: 12-41/h). Nine patients were diagnosed as moderate OSA and the remaining 4 patients were had mild OSA. Ten of the thirteen patients stated that their complaints improved after UPF. The remaining three patient's snoring and nocturnal choking problems continued in spite of UPF. Postoperative AHI was (13 range: 4-20/h) for all individuals. In symptomatic group postoperative mean AHI was 20/h. In asymptomatic group mean AHI was 11/h (4-20). All individuals underwent post-operative NFS. In three symptomatic patients, the obstructive problems were found to be outside of the UPF operation area. Results: UPF is a successful technique for selected patients and NFS can be used preoperatively for OSA patients as a dynamic method to evaluate the obstruction area.