This research studied the surface activation of the acrylonitrile butadiene styrene (ABS) using Co and Ni metal. The parameters affecting the surface activation, namely types and concentrations of activator and reducing agent and reaction time, were studied. This process can be divided by many steps. The first step is to activate the ABS surface using Co and Ni solution. Next step is to reduce metal ions to metal using stannous (II) chloride and sodium borohydride solution. It was found that sodium borohydride solution was quite effective in the reduction of both Ni and Co ions. The results showed the most effective in reduction of metal ions into metals when using 0.5 M sodium borohydride solution at the reduction time of 60 seconds while the stannous (II) chloride solution was not effective. By immersing in a Ni plating bath the Co (or Ni) can then auto-catalytically deposit a Ni film on the ABS. The amount and thickness of Ni coating film was determined by using SEM. It was found that the amount and thickness of the Ni coating film were the highest when using 3 g/L of nickel acetate solution, 0.5 M sodium borohydride solution at 60 s of the reduction time. The characteristics of the coated ABS were checked by tape test according to ASTM D3359, which indicated good adhesion between Ni film and ABS substrate.