Co/Ag multilayers with various Co and Ag layer thicknesses were prepared by alternate vapor deposition of pure Co and Ag. The effect of constituent metal layer thickness on the microstructure and magnetic properties of the films was investigated by transmission electron microscopy, Rutherford backscattering, X‐ray diffraction, and vibrating sample magnetometry. The experimental results show that Co layers grow in an fcc structure with the proper relative thickness of constituent metals. The saturation magnetization and coercive force of the multilayers change significantly with layer thickness of Co and Ag. The mechanisms responsible for the phenomena are discussed.