Definition of prognostic factors for torsion of the testis in children.From January 1986 to December 1996, 91 children were operated for torsion of the testis. Torsions were observed at all ages of childhood, but with two frequency peaks: during the neonatal period and in adolescence. Typical clinical features were observed in only three-quarters of cases.Thirty-nine testes were considered to be necrotic versus 52 with a chance of recovery. Factors of poor prognosis were: neonatal forms, delayed management or tight torsion with several turns. 28 of the necrotic testes were conserved: two were complicated by purulent necrosis, but 14% retained normal trophicity on long-term examination.The possibility of torsion at all ages of childhood and the frequently incomplete clinical features means that emergency surgical exploration must always be performed in the case of testicular pain. A conservative attitude is motivated by the possibility of recovery of testes considered to be necrotic at operation.