Background Any surgical incision can lead to the occurrence of incisional hernia (IH) even laparoscopic trocar incision. IHs typically develop within the first 5 years of surgery; however, their development may be delayed. In large hernias, the amount of viscera which progressively stretches and holds the hernia sac can form a 'second abdomen' making the repair of hernia difficult. Aim IH after abdominal surgery is an important problem. We aimed to evaluate the short-term recurrence rate as well as surgical complications in patients operated with onlay mesh repair technique for large and giant IHs. Patient and methods In our study, we had 40 patients who were complaining of large IH with a defect size of 10 cm or more. All of these patients were operated using the onlay mesh technique in which polypropylene mesh was used. Results A total of 40 cases of IH were repaired with placement of onlay mesh; two (5%) cases developed recurrence. The incidence of seroma in our study was 22.5%, making it the most common complication following the repair of IH. Seroma formation was followed by surgical site infection (15%) as the second most common complication. Conclusion Repair of large and giant IH using prosthetic nonabsorbable mesh has a reasonably good outcome with acceptable rates of recurrence. The technique of mesh placement is still at the surgeon's discretion. However, onlay mesh repair has shown promising results in our study. Seroma is the most common complication following the repair of large and giant IHs.