Background and objectives: The size of the ProSeal laryngeal mask airway in children is determined by the patient’s weight. However, in some instances, an alternative method may be required. This study aimed to compare sizing by the age with conventional PLMA sizing by weight in children. Methods: 80 children with ASA physical status I–II who were scheduled for a routine genitourinary operation were included in the study. PLMA size was chosen by computer generated randomization. The results of age based method were compared with the standard weight–based method. Agreement between both techniques was evaluated with coefficient statistics. Results: Insertion and adequate ventilation were achieved in 77 patients at the first attempt, and 3 patients required a second attempt. Agreement between the two methods of size selection of the PLMA was not statistically significant. Conclusion: Choosing the size of the PLMA in children according to the age based method of the child is valid and practical. In particular, this is an alternative method in situations where the patient’s weight is unknown, such as in emergency situations.