Background: Obstructive sleep apnea syndrome (OSAS) is a condition marked by recurrent upper airway obstruction, snoring, and excessive daytime sleepiness as a result of apnea and hypoapnea episodes during sleep. The present study was conducted to assess impact of denture wearing on retropharyngeal space in edentulous patients. Materials & Methods: 50 edentulous patients of both genders were divided into 2 groups of 25 each. Group I were edentulous patients wearing no denture and group II were wearing denture. Lateral Cephalograph of edentulous subjects and lateral Cephalograph of same edentulous subject wearing complete denture with acceptable vertical dimension of occlusion. Parameters such as retropharyngeal space (Mp-Lp), posterior airway space, apw2-ppw2, and apw4-ppw4 were recorded. Results: Out of 50 patients, 28 were males and 22 were females. In group I and group II, the mean retropharyngeal space (Mp-Lp) was 11.3 mm and 14.5 mm, posterior airway space was 12.3 mm and 15.7 mm, apw2- ppw2 was 13.2 mm and 15.9 mm and apw 4-ppw 4 was 18.4 mm and 20.2 mm respectively. The difference was significant (P< 0.05). Conclusion: Retropharyngeal space (RPS) and posterior airway space (PAS) were found to be reduced in edentulous subjects as a result of anatomical changes that caused a decrease in vertical dimension, which led to the collapse of oro-facial structures, and to increase after wearing complete dentures because the vertical dimension of occlusion was restored.