Mutual diffusion coefficients (interdiffusion coefficients) have been measured of chromium(III) chloride in water at 298.15 K and 303.15 K at concentrations between 0.005 mol‚dm-3 and 0.05 mol‚dm-3 using a conductometric cell. The experimental mutual diffusion coefficients are discussed on the basis of the Onsager-Fuoss model. The equivalent conductance at an infinitesimal concentration of the chromium-(III) ion in these solutions at 303.15 K has been estimated using these results.