Unidirectional and multidirectional laminates of Mg wire‐reinforced PLA‐matrix composites were manufactured by an improved compression molding strategy that allows excellent control on the position and orientation of the wires. Two different types of Mg wires, with and without surface modification by continuous plasma electrolytic oxidation were used, the former to improve the interfacial strength and to reduce the degradation rate of Mg wires in biological environments. The mechanical properties of the constituents as well as of composites were measured before and after degradation by immersion in simulated body fluids and the corresponding deformation, fracture and degradation mechanisms were analyzed in detail. It was found that the presence of the Mg wires improved the mechanical behavior in tension and compression of unidirectional composites in the longitudinal direction (close to cortical bone) and that quasi‐isotropic laminates with tailored properties could be designed from the data of unidirectional composites.This article is protected by copyright. All rights reserved.