ObjectivesA failed first attempt at laryngeal mask airway (LMA) insertion could increase the risk of laryngospasm, hypoxemia, and postoperative sore throat. This study was performed to investigate the risk factors for failed first-attempt LMA placement.MethodsIn total, 461 patients who underwent general anesthesia with a Supreme LMA (Teleflex Medical, Shanghai, China) and who had an American Society of Anesthesiologists (ASA) physical status of I to III were prospectively enrolled. The LMA was inserted after anesthetic induction. We recorded the insertion conditions and each patient’s age, ASA status, body weight, body mass index (BMI), duration of anesthesia, size of LMA, and cuff pressure; the years of work experience of the anesthesiologists; and the use or nonuse of lidocaine gel as a lubricant.ResultsSuccessful first-attempt placement of the Supreme LMA was achieved in 438 (95.10%) patients, while first-attempt placement failed in 23 (4.99%). Significant risk factors for failure of first-attempt LMA insertion included high age, high body weight, BMI of <20 kg/m2, and insertion without using lidocaine gel.ConclusionsA patient age of >61 years, high body weight, BMI of <20 kg/m2, and insertion without lidocaine gel could significantly increase the risk of failed first-attempt Supreme LMA insertion.