BACKGROUND: Sore throat is a common complaint after endotracheal intubation and affected by several factors. The most important causes that affect the incidence and severity of postoperative sore throat is cuff overexpansion. We evaluate the incidence and severity of postoperative sore throat when foam-filled cuff endotracheal tubes and air-filled cuff endotracheal tubes are used. METHOD: Forty patients undergoing general endotracheal anesthesia were allocated randomly to two groups to receive either foam-filled cuff tubes or air-filled cuff tubes. All patients were interviewed 24 hours postoperatively whether they had experienced a sore throat or not by individuals who did not know which tube was used. RESULTS: Incidence of sore throat was 20% in foam-filled cuff group and 50% in air-filled cuff group. In foam-filled cuff group, sore throat was less severe than air-filled cuff group. In air- filled cuff group, sore throat was more severe as intracuff pressure was increased. CONCLUSION: The incidence and severity of postoperative sore throat could be significantly reduced using the foam-filled cuff tubes.