Incisional hernias are caused by the failure of the wall of the abdomen to close after abdominal surgery, leaving a hole through which the viscera protrude. Incisional hernias are repaired by further surgery. Surgical drains are frequently inserted during hernia repair with the aim of facilitating fluid drainage and preventing complications. Traditional teaching has recommended the use of drains after incisional hernia repair other than for laparoscopic ventral hernia repair. More than 50% of open mesh repairs of ventral hernias have drains inserted. However, there is uncertainty as to whether drains are associated with benefits or harm to the patient.