The anisotropic diffusion behavior of Zn in hcp Mg was for the first time experimentally investigated using diffusion couple experiments with Mg single crystals at temperatures between 553 and 603 K (280 and 330 °C). The diffusion coefficients determined from Zn concentration profiles in hcp Mg single crystals are: D⊥hcp−MgZn=4.98×10−5exp(−132725/RT) m²/s along the basal plane and Dllhcp−MgZn=7.33×10−5exp(−135488/RT) m²/s normal to the basal plane. The diffusion coefficient of Zn along the basal plane is about 1.23 times higher than the one normal to the basal plane at the experimental temperatures. Inter-diffusion coefficients of Mg₂Zn₃, MgZn₂ and Mg₂Zn₁₁ were experimentally determined for the first time. In addition, the inter-diffusion coefficients of Mg₁₂Zn₁₃ and Mg₅₁Zn₂₀ were calculated from a multiphase diffusion model.