Background Purpose of this study was to investigate the effects of the vomer flap during cleft palate repair on the incidence and severity of obstructive sleep apnea syndrome (OSAS) in non-syndromic pediatric patients with cleft palate with or without cleft lip (CP +/- L). Methods A retrospective study was conducted in order to analyze and compare polysomnography (PSG) results, regarding apnea-hypopnea index (AHI), oxygen desaturation index (ODI), mean duration of apnea, mean duration of hypopnea, mean oxygen saturation, lowest oxygen saturation, mean desaturation and supine index of patients with CP +/- L. Non-syndromic patients with CP +/- L at age of 2-8 years, who had been operated in our department and had undergone sleep study were included. Syndromic patients, patients with late palate repair or palate fistula and patients who underwent secondary operations were excluded. A total of 17 patients met all inclusion criteria. Patients were divided into two groups according to use of vomer flap (VF) during cleft palate repair (group 1 with VF, group 2 without VF). Statistical analysis of previously mentioned PSG parameters was performed. Results Differences between group 1 (n=7) and group 2 (n=10) regarding AHI (p=0.626), ODI (p=0.695), mean duration of apnea (p=0.305), mean duration of hypopnea (p=0.434), mean oxygen saturation (p=0.221), lowest oxygen saturation (p=0.625), mean desaturation (p=0.240) and supine index (p=0.626) were not found to be statistically significant. 42.8% of patients in group 1 were diagnosed with mild, 42.8% with moderate and 14.2% with severe OSAS. Conclusions Utilization of a vomer flap during cleft palate repair did not have a statistically significant effect on the presence or severity of OSAS. Level of evidence: Level IV, risk/prognostic study.