The dependence of light losses in nanodimensional coatings obtained by sol-gel technology on the viscosity of film forming solutions and on their light absorption at wavelengths of 315, 364, and 400 nm has been considered. It is shown that the number of inclusions and light losses in the coatings are proportional to the viscosity of the solutions. The absence of a reliable correlation between the viscosity and light losses in a film forming solution is accounted for by the deviation of the shape of the particles from a spherical one. Using computer modeling, it has been established that the average size of particles in a coating does not exceed 5 nm and their arrangement is friable. The light losses in the coatings studied are sensitive to the con tent of oxides in a film forming solution and the rate of its deposition onto the substrate.