Multifunctional Langmuir-Blodgett films were prepared using sol-gel derived ZnO and silica nanoparticles synthesized by the procedure of Seelig et al.  and Stöber et al. , respectively. High inherent porosity was observed for ZnO particles (30-40%) by pycnometry, scanning angle reflectometry, N 2 adsorption-desorption and ellipsometric porosimetry methods. Water contact angle of ZnO nanoparticles was determined from the non-dissipative part of the obtained surface pressure-surface area isotherms, and by scanning angle reflectometry measurements in a Wilhelmy film balance. Antireflective and photocatalytically active coatings of ZnO particles were deposited on glass, conductive glass and silicon substrates. The antireflectivity of ZnO LB films was improved by the integration of silica nanoparticles in the LB film. The photocatalytic activity and the mechanical stability of the samples were enhanced by means of surface modification with 3-methacryloxypropyl(trimethoxy) silane.