ABSTRACT Objectives: The objective of this research was a comparative study of the reaction of the tissues of the anterior abdominal wall to the PTFE-endoprosthesis with a DLC-coating at long-term experimental stages. Material and Methods: The study was performed on 110 white laboratory rats divided into two experimental groups. In the first group, a 1.0–1.0 cm PTFE-endoprosthesis fragment was implanted under the skin of the anterior abdominal wall in animals. In the second group, a DLC-coated PTFE-endoprosthesis fragment was implanted into animals. A morphological study of the preparations was carried out after 180 days of the experiment. Results: A morphological study revealed significant differences in tissue reactions to two types of PTFE-endoprosthesis after 180 days of the experiment. Both groups showed no acute inflammatory changes, and the differences were related to the delimiting tissue reactions. The giant cell reaction was observed to a greater extent when uncoated PTFEendoprostheses were used, and type IV collagen fibronectin was accumulated in them. The presence of a DLC coating significantly reduced the degree of this reaction. Also, a significant difference is that the initial PTFE endoprosthesis with micropores is impregnated with plasma and matrix proteins and subsequently grows with collagen fibers. DLC-coating reduces the absorption of proteins in the thickness of the endoprosthesis. Conclusion: The study found that this surface modification of PTFE-endoprostheses significantly affects the nature of the inflammatory and restrictive reactions that determine the bio-integration of the endoprosthesis.