Postoperative pneumascos has always been interesting and provocative for surgeons because its << correct >> disappearance time still remains ill-defined. Fifty-six children, for whom Golstein's intraoperative diagnostic pneumascos was carried out to demonstrate a controlateral hernia during the correction of a unilateral inguinal hernia, were followed up for disappearance of their pneumascos with abdominal radiographs taken at the 4th postoperative hour and on the 1st, 2nd, 4th and 8th days. The children were divided up into three groups: 9 children were younger than 6 months, 20 were 6 to 24 months old, and 27 were older than age 2. The intraperitoneal free air present in all subjects 4 hours after surgery has completely disappeared from the radiographs of the children younger than 6 months on the fourth day, and on the eighth day for the children aged 6 to 24 months, while a trace of subphrenic air still persisted in the 7 % (2 out of 27) of children who were older than age 2. This work is aimed at establishing a correlation between the child's age and the time of disappearance of the pneumascos.