In the years from 1971 to 1980 inclusive, 511 infants under 1 year of age presented with inguinal hernia. Of these, 158 (31%) (149 boys and 9 girls) had incarcerated inguinal hernia. In 151 (95.5%) infants the incarcerated inguinal hernia was reduced by taxis and herniotomy performed 48 to 72 hours later. Seven infants (4.5%) required emergency operation. Of the 142 boys whose incarcerations were reduced by taxis 87 (61%) were contacted and examined. They were aged 10 months to 10 years, 9 months at the time of follow-up. Two boys had testis in the groin presumably hitched up at operation. Testicular volume was assessed in 87 boys using Prader's orchidometer. Two boys had unilateral testicular atrophy. In the remaining 85 boys testicular volume was not different from that of age-matched controls. Our data show that the danger of testicular infarction from an incarcerated inguinal hernia, although real, has been much over-emphasized.