The effects of cobalt content and heat treatment temperature on hardness and wear resistance of nickel-cobalt-phosphorus (Ni-Co-P) are systematically investigated on the electroless alloy deposits composing of cobalt with contents up to 45%. The increase of the cobalt content leads to improved stabilization of grain size and crystallographic structure upon thermal annealing. A moderate annealing temperature of 300°C applied on Ni-45Co-2.6P deposits grants optimum hardness of 959 Hv and relatively low wear loss of 8.85 mg/1000 cycles in abrasive mode, as assessed by Taber abraser wear test. An exclusion of cobalt, however, shows benefit in wear resistance enhancement under the ball-on-disc wear test, where a combined abrasive and adhesive wear is induced in this class of nickel-based alloys.