ObjectiveTo evaluate ultrasound diagnosis of occult inguinal hernia in children. MethodsThe contralateral site of 132 established unilateral inguinal hernia cases was checked by ultrasound and 33 outpatient suspected occult inguinal hernia cases underwent B-mode ultrasonography. [WT5”HZ]Results Occult inguinal hernia was diagnosed in 15 cases (11.4%) in the 132 children,and diagnosis of occult inguinal hernia was founded by ultrasound in 17 out of the 33 outpatient cases. No opposite inguinal hernia developed in the ultrasound negative 117 patients during follow up of 2 to 12 months,and hernia developed in one out of the 16 outpatient cases initially judged as negative by ultrasound. ConclusionUltrasonography is useful for the diagnosis of occult inguinal hernia in children.