The objective of this study is to produce a uniform and consistent nanophase hydroxyapatite (nHA) and poly (lactic-co-glycolic acid) (PLGA) coating on three-dimensional magnesium (Mg) implants using electrophoretic deposition (EPD) process. Mg is biodegradable, mechanically strong, and promising for orthopedic implant and device applications. However, currently available Mg and its alloys degrade too rapidly to meet clinical needs. To control Mg degradation and promote bone ingrowth, nHA/PLGA composite microspheres were synthesized and deposited onto Mg substrates using EPD process. Annealing was applied to improve the coating adhesion. The surface morphology, composition, and coating cross-section were examined using a scanning electron microscope and energy dispersive X-ray spectrometer. The results showed the presence of calcium, phosphorous, carbon, and oxygen peaks, indicating the successful deposition of nHA/PLGA microspheres on Mg. The corrosion resistance of the coated Mg was evaluated using the Tafel test. The results showed that the nHA/PLGA composite coating improved the corrosion resistance of Mg.