We report herein our results of routinely performing tension-free repair for midline incisional hernias larger than 3 cm using a woven polypropylene graft between January 1990 and December 1995. Included in this study were 45 patients, 34 (73.1%) of whom had previously undergone a primary repair which had failed. The follow-up period ranged from 3 to 56 months with a mean of 36 months. Only one patient (2.2%) suffered a recurrence of the hernia. Although three (6.6%) developed a wound infection, one (2.2%) developed a wound sinus, and two (4.4%) developed wound seroma, none of these complications required removal of the graft. The findings of this study led us to conclude that Prolene grafts could be used as routine prosthetic material in the repair of incisional hernias. Moreover, during the follow-up period we observed that the modifications we made in the operative technique had a significantly positive effect on the outcome of the patients.