Electroless nickel plating and immersion gold plating are key inter-connection processes in the manufacture of highly reliable printed circuit boards (PCBs) . However, an extraneous Ni deposition has often been observed between the copper patterns due to the adsorption of Pd on the resin. To develop a method for direct electroless nickel plating on copper circuits without Pd activation, we introduced hydrazine as a secondary reducing agent for the initiation of the plating, because hydrazine can generate Ni nuclei on the copper surface in the initial stage. This process eliminates the Pd activation process, avoiding the extraneous deposition on the resin and achieving highly selective nickel deposition on the copper circuits.