We reviewed 785 patients with varicocele testis who underwent high ligation of internal spermatic vein at Kasukabe City Hospital between 1969 and 1985, and found only 3 patients suffering from postoperative hydrocele testis. Analysis of the hydrocele content in one case revealed a high protein level, which suggested that the etiology of the hydrocele after high ligation is of lymphatic origin, so that it is important to preserve the lymphatics of spermatic cord in order to prevent postoperative hydrocele.