Many anaesthetists have found the size 1.5 classic Laryngeal Mask Airway unsuitable for use in children under 10 kg, whereas recent studies evaluating the ProSeal Laryngeal Mask Airway (PLMA) show high success rates, even during laparoscopic surgery. Our routine practice has been to use tracheal intubation for inguinal herniotomy in children weighing less than 10 kg. Following the introduction of the PLMA to our hospital, we decided to audit our use of the PLMA 1.5 in this group of patients. We included 20 consecutive infants, aged less than six months and weighing 5 to 10 kg. We recorded patient, anaesthetic and insertion details, device performance data and complications. No aspect of anaesthetic practice was changed by involvement in this audit. The PLMA was inserted successfully at the first attempt in 85% (17/20) of infants. Overall successful insertion occurred in 90% (18/20) and satisfactory airway maintenance was provided for the duration of anaesthesia in 90% (18/20). The mean leak pressure was 24 cmH2O (range 15 to 30 cmH2O). We found the 1.5 PLMA provided a satisfactory airway in 90% of infants. This report adds to the evidence that the PLMA 1.5 can provide a satisfactory alternative to intubation in selected infants.