To date, allohernioplasty of giant postoperative ventral hernias retains high postoperative mortality and a significant number of postoperative complications. The purpose of the study is to investigate the possibility of intraperitoneal use of polypropylene and composite implants in allohernioplasty of postoperative giant ventral hernias by studying the morphological changes of the great omentum. The results of surgical treatment of 146 patients with postoperative giant ventral hernias were investigated. To this group of patients with allohernioplasty by the method onlay was performed 22 (15.1%) patients, by the method sublay – 46 (31.5%), by the method inlay – 52 (35.6%), with intra-abdominal placement of the mesh by the method onlay (intraperitoneal onlay mesh) – 26 (17.8%). 32 (21.9%) patients who underwent surgery using the sublay method polypropylene implant was fenced off from the abdominal organs with a great omentum, 22 (15.1%) patients operated on by the intraperitoneal onlay mesh method composite implant was also fenced off from the abdominal organs by a great omentum. In 8 (5.5%) patients from the group of patients who were operated on by the sublay method and in 6 (4.1%) – operated by the intraperitoneal onlay mesh method for 14-18 days patients developed signs of chronic intestinal obstruction, where the cause was postoperative adhesive illness. The study of the effect of polypropylene prosthesis on a great omentum was performed on 8 outbred dogs and 6 outbred mature dogs, who were implanted with a composite mesh unilaterally covered with oxycellulose. The polypropylene implant has been shown to have a greater capacity for the development of adhesive processes. However, if a great omentum to protect this prosthesis from the abdominal cavity then the first zone (active inflammation) spread in 155 microns (increase in the number of blood capillaries of the microcirculatory bed, thickening of the arterioles wall, venous full blood flow, diapedesis of leukocytes through the wall of the blood cells), the second zone (sclerosis) – up to 40 microns (increase in the number of macrophages and lymphocytes. proliferation of fibroblasts). In the future, the structure of the omentum was almost indistinguishable, so with allohernioplasty by the developed method, it was possible to prevent the development of adhesive disease on the intestine. This study confirmed the limited spread of the inflammatory response, which allows the implant of a polypropylene mesh on a great omentum. In the composite mesh, the composite mesh was spliced with surrounding tissues from the side where there was no gel coating, and from the side of the salivary coating, the “readiness” to spread the inflammatory process (vasculitis with pronounced lympho-plasmocytic infiltration of the vessel walls and perivascular ductus), therefore, left it is also necessary to enclose it with a large omentum from intestium.