Objectives. To determine the incidence of external spermatic veins at inguinal varicocelectomy. Methods. A prospective study was performed by making intraoperative observations on 78 varicocelectomies (47 patients) performed by a single surgeon. All patients were referred for evaluation of male infertility and had a palpable varicocele present when examined while performing a Valsalva maneuver in the upright position. Varicocelectomies were performed via the inguinal approach using x2.5 loupe magnification. Presence of external spermatic veins was defined as visualization (with x2.5 loupe magnification) of veins on the floor of the inguinal canal traveling posterolateral to the spermatic cord that then subsequently exited the spermatic cord before passing through the internal inguinal ring. Age, anesthetic technique, and need for incision of the external inguinal ring were also recorded for each patient. Results. One third of patients had undergone left-sided varicocelectomies, while two thirds had undergone bilateral procedures. External spermatic veins were identified in 15% of left-sided varicoceles and 19% of right-sided ones. Of 31 patients undergoing bilateral varicocelectomies, 19% had at least 1 external spermatic vein. Of these patients, only 2 (7%) had a unilateral right external spermatic vein, none had a unilateral left external spermatic vein, and 4 (13%) had bilateral external spermatic veins. Overall, of all patients studied, 16% had at least 1 external spermatic vein. Follow-up at 1 year showed no evidence of clinical recurrence in any patient. Conclusions. These results emphasize the importance of distal gonadal venous anatomy in the surgeon's choice of the proper approach to varicocele repair, since external spermatic veins are only accessible via an inguinal approach.