From 1978 to 1985, 679 boys were operated for an inguinal hernia. 3 groups of patients must be considered. The bilateral inguinal hernias group (119 children) 73 patients were operated on both sides. 46 presented signs of hernia on the opposite side after the first operation and were operated again. In this group, there is a more important frequency of premature. But the classical notion that bilateral hernia are more common when the presenting hernia is on the left side, is not noticed. As a matter of fact, among the 46, there were 33 children operated at first on the right side. If a systematic bilateral exploration had been realised, it would here been useless in 82 per cent of the cases. The incarcerated inguinal hernia group 177 (26%) children were hospitalised for an incarcerated inguinal hernia diagnosis. 23 infants required emergency operation. Mostly, it was the first episode of a right hernia in a child under 3 months of age. 8 times a testicular infarction was noticed. The incidence of testicular lesion following incarceration of inguinal hernia is more important that the testicular atrophy after primary hernioplasty. This justify the surgical treatment for children of any age. The premature group 126 children were premature infants. In this group, a more important frequency of bilateral and incarcerated hernias are noted. 24 among these patients presented recurrent apnea episodes. To 8 of those children, the intervention was probably a benefit for the evolution of their apneas.(ABSTRACT TRUNCATED AT 250 WORDS)