BACKGROUND: Sore throat is one of the most common complications of intubation. There are many factors that affect the incidence of sore throat and the succinylcholine-induced myalgia. Our study is to reveal the influences of these factors on the postoperative sore throat and the succinylcholine-induced myalgia. METHODS: One thousand and seven patients in ASA class I or II undergoing elective surgery under general anesthesia were studied, except patients undergoing brain surgery, open heart surgery, operation in oro-, naso-pharynx and larynx, and uncooperated psychiatric. We checked age, sex, patient controlled analgesia and nasogastric tube, size and kind of tube, operation position, duration of intubation and anesthetic agent. At 24~38 hours after operation, the patients were questioned about pre- and postoperative sore throat, or myalgia. RESULTS: Sore throat after endotracheal intubation developed more frequently in woman (32.8%) than man (25.9%). The older the patients, the lower the incidence of sore throat (p<0.05). The longer the anesthesia duration, the lower the incidence of sore throat (p<0.05). Succinylcholine, patient controlled analgesia, nasogastric tube, endotracheal tube, operation position, maintenance anesthetic agents and the amount of smoking did not affect the incidence of sore throat. The incidence of succinylcholine-induced myalgia was lower in elderly or patients who were administered nondepolarizing muscle relaxant. CONCLUSIONS: The incidences of sore throat and myalgia were 29% and 15%, respectively. There were significant differences in incidence of sore throat and myalgia depending on the gender, age, duration of operation, but the controllable factors which reduce the incidence of sore throat were not found. Nondepolarizing muscle relaxants could reduce the occurrence of postoperative myalgia.