The laryngeal mask airway (LMA) was recently introduced in pediatric anesthesia as an alternative to the face mask or tracheal intubation for airway maintenance. The authors report their experience with LMA on 120 consecutively treated children who underwent elective inguinal herniorrhaphy or orchidopexy. The patients were monitored with electrocardiograms, noninvasive blood pressure determinations, pulse oxymetry, and capnometry. Anesthesia was induced and maintained with halothane, nitrous oxide, and oxygen. There were 96 males and 24 females; the age range was 1 month to 14 years (average, 3.2 years). They weighed between 2.5 and 46 kg (mean, 14 kg). Patients were allowed to breath spontaneously until anesthesia was deep enough (average, 6.3 minutes; range, 2 to 15 minutes). The appropriate-size LMA was inserted and inflated, and patients were divided into three groups. Group I patients (n = 24) weighed 2.6 to 6 kg and received LMA size no. 1. Group II (n = 84) weighed 6 to 30 kg and received LMA size no. 2. Group III (n = 12) weighed more than 30 kg and received LMA size no. 3. Patients in groups II and III breathed spontaneously; those in group I were on volume-controlled ventilation. The LMA was easily inserted in 115 patients (95.8%)--on the first attempt in 100, and on the second attempt in 15. In five patients, LMA was successfully inserted on the third attempt. The ease of insertion was not significantly different between the groups. Anesthesia was maintained by halothane (mean, 1.34%; range, 0.8% to 2.54%) for an average of time of 39.2 minutes (range, 15 to 90 minutes).(ABSTRACT TRUNCATED AT 250 WORDS)