The Authors have examined, over a period of two years, 110 patients presenting with varicocele and infertility. Varicocele has an incidence of 40% in male sterility, causing oligozoospermia and asthenospermia. Patients first underwent non-invasive tests such as Doppler and echo-Doppler tests. According to the Authors experience, Doppler speedometry is decisive for the diagnosis of both idiopathic and subclinical varicocele, for the post-operative control of microsurgical anastomosis, and for the intra-operative detection of accessory spermatic veins. The surgical technique used by the Authors is the modified Palomo technique, but other techniques are investigated as well. Post-operative results, concerning both spermiogram and relapses are also evaluated.