This case report describes the management of a horse with a very large incisional hernia. The hernia was corrected surgically with primary closure of the body wall and a polypropylene mesh overlay. Post-operative complications included infection of the surgical site and mesh prosthesis, which necessitated surgical removal of the mesh. Despite a prolonged recovery period, a good functional and cosmetic outcome was achieved. Many horses that have a severe epidode of colic and undergo an emergency exploratory celiotomy subsequently have incisional complications. These complications may include hemorrhage, hematoma or seroma formation, peri-incisional edema, dehiscence, drainage and/or infection, herniation, and suture sinus formation. Incisional complications often prolong post-operative recovery time and may necessitate additional surgeries. This case report describes the management of a very large incisionall hernia, which developed following colic surgery in a horse.