This paper presents an experimental study on the influence of anionic surfactant sodium dodecyl sulfate (SDS), pH, substrate finishing and annealing temperature on the corrosion resistance of electroless nickel phosphorus (Ni-P) coatings using electrochemical techniques and optimization of process parameters based on the Taguchi method. Parameters were selected in three levels and L9 from orthogonal robust array design was used. Corrosion performance of the electroless Ni-P coatings was evaluated by polarization and electrochemical impedance spectroscopy (EIS). Scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis were used for studying surface morphology and chemical composition of the electroless Ni-P coatings. The results showed that SDS surfactant causes increasing of corrosion resistance and improves surface morphology. Finally, optimum conditions were achieved as, surfactant concentration: 1.5 g L-1, pH: 5.5, substrate finishing provided with emery paper no, 2000, and annealing temperature of 200 A degrees C.