Changes in volume and histology of the testis in adolescent varicocele is a dynamic and progressive process. Testicular damage of adolescent varicocele can be prevented by prophylactic surgery but not all adolescents with varicocele require such measures. However, semen analysis cannot serve as an indicator of damage in these patients, and size and symptoms are also not sufficient. Therefore both testicular volume and a gonadotropin-releasing hormone stimulation test are being used for early detection of testicular damage. Physical examination is the gold standard for the diagnosis of varicocele. Both gray-scale and colour Doppler sonography can be used as adjuncts. The operative techniques for varicocele are numerous, but can be categorized into retroperitoneal high ligation and artery-sparing inguinal ligation. Laparoscopic ligation is gaining popularity, and for selected cases interventional radiographic embolization can also be used. Currently no single or group of tests can accurately predict whether an adolescent with varicocele will be fertile. Thus, at least yearly follow-up of those patients who are not initially indicated for surgery should be recommended.