The mathematical and computational modeling of the lubricated contact between bearing surfaces is presented to analyze the sliding friction using a realistic 3D model on a microscopic scale. The fluid–structure interaction model evaluates the effects of lubricant film thickness on friction in hydrodynamic and mixed lubrication regimes. Higher contact pressures are seen at the peaks of asperities, especially during mixed lubrication, in which the fluid volume is smaller. Calculated friction coefficients from a homogenization procedure of shear and normal forces in the hydrodynamic and mixed lubrication, close to 0.0045 and 0.014, respectively, were accurate and within the range specified in the Stribeck curve. Results demonstrate the computational model allows examining the effects of lubrication on contact between rough surfaces.