Metallic materials, from which numerous works of art are built, should be protected from the effects of corrosion processes. If materials are not adequately protected it may cause their continuous deterioration which results in significant material costs of repair or replacement and environmental pollution which may have significant consequences on human and the environment. Air pollution (emissions of SO2, O2, NOX) and meteorological conditions (temperature, relative humidity, acid rain) play a key role in the atmospheric corrosion of materials, especially of bronze monuments causing invaluable damage due to the loss of original material. One of the possibilities of protecting the bronze is the modification of the surface with a thin film of organic molecules so-called self – assembled monolayers. The aim of this study was to examine the possibility of protecting bronze from corrosion caused by acid rain, by using self – assembled monolayers of long-chain phosphonic acids. With this aim, dependence of protection on the parameters influencing the formation of the self- assembled monolayers and the manner of protection application is examined. Testing of protective properties was carried out in a solution that simulates acid rain with a pH of 5. Protective action of the obtained thin films was determined by electrochemical methods: Tafel extrapolation method, linear polarization and electrochemical impedance spectroscopy. Apart from electrochemical testing, samples were subjected to scanning electron microscopy and Fourier transformational infrared spectroscopy to gain qualitative and quantitative information on the obtained protective layer. The existence and effectiveness of the protective film of 16 - phosphonohexadecanoic acid on the applied materials was confirmed indicating the improvement of corrosive resistance, where by a higher level of protection is achieved with the immersion process.