Magnesium alloy is highly potential material for biodegradable implant application. Due to limitations in conventional machining methods, non-traditional machining method such as electrical discharge machining (EDM) die sinking process is proposed to produce intricate shape with tight tolerance on magnesium alloy. Nine EDM experiments with three levels and four parameters were conducted using Taguchi method on AZ31 magnesium alloy to explore the optimum machining parameters. It was found that pulse on-time was the most significant parameter affecting the surface roughness (Ra) of the machined surface. The optimum EDM condition obtained was 47 A peak current, 80 V voltage, 16 μs pulse on-time and 512 μs pulse off-time. A confirmation test was conducted and the result shows 95.5 similarity with the predicted Ra. However, the formation of cracks and craters were found on the machined surface area. It is proposed to solve this problem by applying powder mixed EDM method in future research work. © 2016 The Authors.