Purpose: Varicocele ligation in children and adolescents has been advocated for left testicular growth arrest. We report our experience with this population as well as the results of the microscopic inguinal technique. Materials and Methods: Between 1994 and 1999, 184 children and young adults presented with unilateral left varicoceles. At presentation 171 patients were asymptomatic and 13 had pain. Testicular measurement was assessed with calipers in 158 cases and ultrasound in 26. Surgery was performed using a microscopic inguinal technique in 58 patients and loupes in 16 of those who presented with left testicular growth arrest initially or who had growth arrest while under observation. Only one child underwent surgery for pain alone. Results: Patient age at presentation ranged from 5 to 22 years, and 70% presented between the ages of 12 and 16 years. Of the 13 patients with pain ages ranged from 13 to 22 years and 6 (46%) also had left testicular growth arrest. Initially, 109 (60%) boys were found not to have left testicular growth arrest and were followed, while 56 (30%) with left testicular growth arrest (ages 9 to 22 years) underwent surgery and 19 were lost to followup. Left testicular growth arrest developed in 17 (15%) of the followed group (ages 11 to 17 years) after 6 to 41 months (average 22) of observation and they underwent surgery. Postoperatively, varicocele disappeared in 66 (89%) patients and it was smaller in 8, in whom 8 loupes were used in 2 and the microscope was used in 6. Of the 36 patients who returned for postoperative measurement 30 (83%) had catch-up growth, while 6 did not. No hydroceles were noted. Conclusions: Varicoceles can be found in boys as young as 5 years and left testicular growth arrest as early as 9 years. As left testicular growth arrest can develop if not present initially, these boys must be followed with serial testicular measurements before and after puberty until late adolescence. Microscopic inguinal ligation results in complete resolution of the varicocele in almost 90% of patients with no complicating hydroceles. Left testicular catch-up growth can be expected in more than 80% of patients at any age.