In this paper we make use of a new theory of diffusion in antistructurally disordered intermetallic compounds having the B2 structure. The theory is based around unit processes consisting of six-jump cycles that can be assisted by intrinsic and extrinsic atoms of either atomic species. This theory is applied to chemical and tracer diffusion in AgMg. It is shown that fitting the theory to chemical diffusion data at one temperature enables the ordering energy and asymmetry parameter to be determined. This then provides for the determination of the Ag and Mg tracer diffusivities, the thermodynamic factor and the tracer correlation factors for Ag and Mg diffusion. There is good agreement of the predicted tracer diffusivities with experimentally determined ones.