The aim was to evaluate the value of ultrasound diagnosis of spermatic cord hydrocele as a cause of inguinal swelling or mass in children. Clinical and ultrasound (US) findings and surgical procedures of 27 children with spermatic cord hydrocele were reviewed. All children, except one, were referred for US because of suspected inguinal hernia, hydrocele or inguinal mass. In one child, the US examination was performed to confirm the diagnosis of a spermatic cord hydrocele. An encysted hydrocele was diagnosed in 24 out of 27 cases, whereas a funicular type of spermatic cord hydrocele was found in the remaining 3 cases. Internal septa were seen within the fluid mass in four patients. 23 children underwent surgical exploration that confirmed the US diagnosis. Three children with encysted-type hydrocele were only followed clinically and by US, and one was lost from follow-up. US examination is a very sensitive and accurate method for diagnosis of this entity and for exclusion of other lesions in this region.