In this study, electroless nickel (EN) plating on acrylonitrile butadiene styrene (ABS) engineering plastic using room temperature ionic liquids (RTIL) was studied. Electroless plating is a fundamental step in metal plating on plastic. This step makes the plastic conductive and makes it possible to a homogeneous and hard plating without using any hazardous and unfriendly chemical such as palladium, tin, etc. In the industry there are many distinct chemical materials both catalysts and activation solutions for the electroless bath which is one of the most important parts of the process. In this study the effects of the ionic liquid, plating time, and sand paper size were investigated on electroless nickel plating. The etching and the plating processes were performed with environmentally friendly chemicals instead of the chromic and sulphuric acids used in the traditional processes. Experiments were carried out with and without ionic liquid, EMIC, 1-ethyl-3-methyl imidazolium chloride (C6H11N2Cl), and with 400, 500 and 800 grit sandpaper with the application of the sand attrition process and 70, 80, and 90 degrees C bath temperatures with 30, 60, and 90 minutes of deposition time. The surface morphology and the thickness of deposit analysis were performed using the Fischer scope X-Ray XDL-B System, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Due to the results of the experiments and analysis, the electroless nickel plating on ABS plastic was a success. The best plating was obtained at 5.010 mu m as the maximum plating thickness, at 90 min of plating time and 80 degrees C as the plating bath temperature for electroless nickel plating on ABS plastic whit the surface activated with 800 grit sandpaper using EMIC ionic liquid.