Vasectomy has become a popular method for male sterilization and this, in tum, has been followed by an increase in the number of patients requiring vasectomy reversal. Recently, many authors have reported a high success rate of vasovasostomy using microsurgical techniques. However, a significant discrepancy exist between the anatomical patency rate and pregnancy rate despite improvements in surgical techniques. Number of 420 patients who underwent vasovasostomy by a modified one layer reanastomosis from January 1986 to December 1994 were reviewed. Of the total, Complete follow up were possible in 115 patients. Of the 115 patients, 74 patients were treated by macroscopic reanastomosis, and microscopic technique were applied in 41 patients. Duration of vasal obstruction, gross apperance of vasal fluid, operative method, presence or absence of sperm and sperm granuloma, and results of postoperative semen analysis were analyzed as factors influencing the pregnancy rate. Success rates for patency and for pregnancy were 81% and, 42% respectively. Rate of pregnancy were increased if there were shorter periods of obstruction(<10years), bilateral observation of watery vasal fluid, presence of sperm bilaterally, bilateral presence of sperm granuloma at the vasectomy site, and normal results on postoperative semenalysis. With these results, we can conclude that all factors mentioned may affect the success rate of pregnancy following vasovasostomy.