OBJECTIVE : Closure of the processus vaginalis (PV) is considered as the last step of testicular descent. Therefore, patent processus vaginalis (PV), and inguinal hernias are linked to cryptorchidism. As the National Australian incidence of orchidopexy has decreased over the previous 20 years, we aimed to explore the incidence of inguinal herniotomy (including hydrocele) over time in Australia. METHODS : The National Department of Human Services (DHS) database, and Bureau of Statistics database were obtained for the years 1998-2017. The numbers of inguinal herniotomies in patients aged 0-4, 5-14 and 15-24 yearswere examined with ethical approval. RESULTS : Over the 20-year period, over 87,000 inguinal herniotomy procedures were performed in males. The incidence per year in males decreased across all ages over the 20-year period, but was most pronounced in infants and toddlers. Similar to males, the incidence in females decreased over time, with the ratio of procedures per head of population decreasing in children under 5 years of age. The ratio of male: females varied according to ages, and was between 2.8 and 6.2 males: 1 female. CONCLUSIONS : This study suggests that fewer 0-4-year olds are undergoing inguinal herniotomy, compared with 20 years ago. This is likely due to a change in practice for the management of unilateral symptomatic hernias, from routine bilateral herniotomies, to unilateral surgery. As well as less aggressive surgical intervention for hydroceles in boys. METHODS : III.