The aim of this paper is to evaluate the role of Doppler and echo color-Doppler in the microsurgical treatment of varicocele. Since December 1993, 87 consecutive patients underwent microsurgical treatment of varicocele. The study demonstrates that Doppler and Color-flow-Duplex scanning provide an accurate, non-invasive method to identify the position of accessory spermatic veins, evaluating at the same time the flow characteristics of the microsurgical anastomosis.