The paper presents the results of the study aimed at determining the elastoplastic properties of an Al/Cu bimetallic sheet consisting of aluminum and copper layers, which were joined by cold rolling. The values of elasticity coefficients in three orthotropic planes as well as the Kirchhoff modulus, and coefficient of internal friction in the perpendicular direction to the lamination were determined. The subjects of the analysis were also the values of limit stresses, uniform energy of elastic and plastic strain per unit volume, and coefficients of the hardening curve and normal anisotropy. The tests were carried out on bimetallic specimens with varying thicknesses of the copper layer, cut from the Al/Cu sheet in the direction of rolling and in the direction perpendicular to it. Two methods of determining the directional values of mechanical parameters were used in the tests, i.e., the uniaxial quasi-static tensile test and the dynamic acoustic resonance method. It was concluded that these methods made it possible to determine directional elastoplastic properties of the Al/Cu bimetallic sheet taking into account the variable share of components in the bimetal and the direction of cutting out specimens from cold-rolled sheet.