Additive manufacturing (AM) of the complex devices for energy application remains an almost unexplored area, and the harsh acidic environment also limits the application of AM parts in water splitting for hydrogen production. Here, bipolar plates (BPs), which are used to transport reactants/products and conduct electrons in proton exchange membrane electrolyzer cells (PEMECs), are printed from stainless steel (SS) with selective laser melting (SLM). Then surface treatments are employed on those BPs by thin film electroplating with Au, and the protective thin layer enables the utilization of AM SS parts to both cathode and anode sides of water electrolyzer cells and exhibits superior corrosion resistances and electronic conductivities. The Au-coated AM SS BPs deliver a low interfacial contact resistance (6.4 m Omega cm(2) under 1.45 MPa) and an excellent performance in PEMECs (1.71 Vat 2 A/cm(2)), and maintain a remarkable durability in the simulated anode environment compared with the uncoated AM SS BPs and conventional graphite BPs. This approach demonstrates the possibility of 3-dimensional printing fully integrated water electrolyzer cells at both anode and cathode sides.