The size 1 laryngeal mask (LMA1) was studied prospectively in a series of 37 infants (weight less than 6.5 kg) undergoing 42 routine surgical procedures. LMA1 insertion was successful at first attempt in 80.9% of all cases and a good airway control was obtained in 93%. The most frequent cause of insertion failure was an insufficient depth of anaesthesia. Only one incident occurred peroperatively. The recovery incidents rate, higher than in other studies, was mainly due to the laryngeal hyperreactivity of infants. LMA1 provides high safety for infant anaesthesia woith food working conditions for bot anaesthetist and surgeon. However, an accurate determination of the anaesthesia level and a close monitoring of recovery are strongly recommended.