Purpose To evaluate the effectiveness of antegrade sclerotherapy (AS) for the treatment of primary varicocele in children. Material and Methods Retrospective study of the charts of 30 boys who underwent AS between 7/2005 and 6/2009 at our institution. Indication for treatment was grade II and III varicocele (Tauber classification), confirmed by clinical and ultrasound (US) examination. Three per cent ethoxy sclerol was the sclerosing agent. Follow up included clinical examination and Doppler US 3 months after the procedure and then yearly for at least 2 years. Results 30 boys (mean age 14 years, range 12 – 17 years) with 31 primary varicoceles underwent AS as an outpatient procedure. In 28 boys, varicocele was on the left side, and one patient each demonstrated bilateral and right sided varicocele, respectively. Varicocele was grade II in 13 patients and grade III in 17 patients. Follow-up including Doppler US was 26 months (range 4-51 months). AS was successful in 28 patients resp. 29 varicoceles (93.5%). 2 patients had a persistent varicocele, and they had repeat AS successfully (no recurrence at follow-up). There were complications after surgery in 2 (6.6%) patients (1 superficial wound infection, 1 scrotal haematoma). No hydrocele and no testicular necrosis was observed. Conclusions AS is an efficient minimally invasive surgical procedure for the treatment of varicocele in adolescent boys. Surgery may be performed as an outpatient procedure. During a follow-up of more than 2 years, we observed no serious side effects. To evaluate the effectiveness of antegrade sclerotherapy (AS) for the treatment of primary varicocele in children. Retrospective study of the charts of 30 boys who underwent AS between 7/2005 and 6/2009 at our institution. Indication for treatment was grade II and III varicocele (Tauber classification), confirmed by clinical and ultrasound (US) examination. Three per cent ethoxy sclerol was the sclerosing agent. Follow up included clinical examination and Doppler US 3 months after the procedure and then yearly for at least 2 years. 30 boys (mean age 14 years, range 12 – 17 years) with 31 primary varicoceles underwent AS as an outpatient procedure. In 28 boys, varicocele was on the left side, and one patient each demonstrated bilateral and right sided varicocele, respectively. Varicocele was grade II in 13 patients and grade III in 17 patients. Follow-up including Doppler US was 26 months (range 4-51 months). AS was successful in 28 patients resp. 29 varicoceles (93.5%). 2 patients had a persistent varicocele, and they had repeat AS successfully (no recurrence at follow-up). There were complications after surgery in 2 (6.6%) patients (1 superficial wound infection, 1 scrotal haematoma). No hydrocele and no testicular necrosis was observed. AS is an efficient minimally invasive surgical procedure for the treatment of varicocele in adolescent boys. Surgery may be performed as an outpatient procedure. During a follow-up of more than 2 years, we observed no serious side effects.