A comparative analysis of the proliferative activity of inflammatory infiltrate cells and the distribution of collagen type I and III in granulomas formed in the area of contact of mesh materials made of polypropylene (PP Std Light) and titanium-coated polypropylene (TiMesh) was performed via polarized microscopy and immunohistochemical detection of Ki-67 protein. Mesh materials were implanted in the soft tissues of the lumbar region of rats. The number of proliferative cells around implants made of the standard polypropylene (PP Std Light) 7 days after the operation was detected with the use of antibodies to Ki-67 protein to be less than the number of those around titanium-coated polypropylene (TiMesh) (29.1 ± 5.7 and 33.6 ± 3.1%, respectively, p