Among the treatments of idiopathic hydrocele cutting a window in the tunica vaginalis testis stands out as the choice treatment, the procedure being simple and the results of good quality. In the first stage, the two layers, visceral and parietal, of the tunica are folded separately to form the edges of the window. In the second stage the parietal layer of the window is attached to the dartos which remains united with the underlying subcutaneous layer, forming an excellent tract for lymph drainage. Thus, the anatomical and physiological objectives of the operation are reached: the testicular "cockpit" and the protective function of the tunica vaginalis are preserved. In a series of 83 patients operated upon and followed up for up to 5 years, 9 out of 10 were cured by this method without unwanted sequelae.