Background: Incisional hernia repair is a frequent surgical procedure, but perioperative risk factors and outcomes have not been prospectively assessed in large-scale studies. The aim of this nationwide study was to analyze surgical risk factors for early and late outcomes after incisional hernia repair. Study Design: We conducted a prospective nationwide study on all elective incisional hernia repairs registered in the Danish Ventral Hernia Database between January 1, 2007 and December 31, 2010. Main outcomes measures were surgical risk factors for 30-day readmission, reoperation (excluding recurrence), and mortality after incisional hernia repair. Late outcomes included reoperation for recurrence during the follow-up period. Follow-up was obtained by merging the Danish Ventral Hernia Database with the Danish National Patient Register. Results were evaluated by multivariate analyses. Result: The study included 3,258 incisional hernia repairs. Median follow-up was 21 months (interquartile range 10 to 35 months). The 30-day readmission, reoperation, and mortality rates were 13.3%, 2.2%, and 0.5%, respectively. Advanced age, open repair, large hernia defect, and vertical incision at the primary laparotomy were significant independent risk factors for poor early outcomes (p < 0.05). The cumulated risk of recurrence repair after open and laparoscopic repair was 21.1% and 15.5%, respectively (p = 0.03). Younger age, open repair, hernia defects >7 cm, and onlay or intraperitoneal mesh positioning in open repair were significant risk factors for poor late outcomes (p < 0.05). Conclusions: Elective incisional hernia repair were beset with high rates of readmission and reoperation for recurrence. Readmission and reoperation for recurrence were most pronounced after open repair and repair for hernia defects up to 20 cm. Additionally, sublay mesh position reduced the risk of reoperation for recurrence after open repairs.