The researchers studied a group of azoospermic patients with obstructions of the seminal canals and a group of oligoasthenospermic patients suffering from varicocele in order to analyze the factors that influence the success of surgery aimed at recovering fertility. In the 46 patients suffering from obstructions of the deferent duct and the extremity of the epididymis, the time factor proved decisive if the obstruction lasted longer than 6 years: in this case, damage to the seminiferous tubules is not reversible. With obstructions dating back less than 4 years, the causes and the location of the obstruction are more incisive. Success was achieved in 100% of vasectomy cases and in 37.5% of epididymal-deferential anastomoses. In research literature, the superiority of microsurgery for treating these types of pathologies is taken for granted. In patients affected by oligoasthenospermia the effectiveness of laparoscopic ligation of the spermatic veins was compared to that of the Belgrano I technique. Of the 30 patients with bilateral varicocele and oligoasthenospermia dating back less than 4 years, 73.3% of the 15 patients operated on using the Belgrano 1 technique experienced sperm normalization; in the 15 cases operated on using laparoscopic ligation of the spermatic canals, normalization was much less frequent. Seventy-five percent of another group of 40 patients whose infertility did not have a duration of longer than 4 years and were operated on using microsurgery techniques were normalized. The percentage of the 60 oligoasthenospermic patients for longer than 6 years normalized was 16.6%.