Experience with several incarcerations that resulted in emergent surgery for children with known indirect inguinal hernias prompted this review to determine if there is an optimal time after hernia diagnosis during which elective repair should be undertaken to avoid incarceration. Over a 30 month period, 228 children less than 10 years of age underwent 303 indirect inguinal hernia repairs. They were analyzed for age, sex, interval between diagnosis and repair, predisposing conditions, major complications, and length of hospitalization. Excluded were 21 children who presented with incarceration of a previously undiagnosed indirect inguinal hernia that required operative reduction, 13 children with conditions predisposing to indirect inguinal hernia, and 53 children for whom the interval between diagnosis and repair was unknown, leaving a study group of 141 children who underwent 190 indirect inguinal hernia repairs. Nearly 13% (18 of 141) of the children developed incarcerated hernia prior to elective repair. Compared to children who underwent repair of a reducible indirect inguinal hernia, those with incarceration were more likely (p less than 0.05): 1) to have major complications (11% vs 0.6%), 2) to have a shorter interval between diagnosis and repair (26 vs 49 days), 3) to be younger (7.5 vs 25.6 mos), and 4) to require greater than 24 hours of hospitalization. Had children with reducible incarcerated indirect inguinal hernia been hospitalized and undergone repair 24 to 48 hours later, 83% of subsequent incarcerations would have been prevented. Furthermore, this experience supports the recommendation that for healthy children less than 10 years of age, indirect inguinal hernia repair should be performed on a semi-elective basis within 7 days of diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)