The convection method was used to determine the translational diffusion coefficients for the diffusion of fullerene C₆₀ in organic solvents at 295 K. The Stokes-Einstein radii for a hydrodynamically equivalent nondeformable sphere were calculated. The linear size of species responsible for mass transfer during isothermal diffusion in methylmorpholine and methylpyrrolidone were found to be 3 and 10 times larger than the size of the C₆₀ molecule. The possible role of the effects of solvation and aggregation in the phenomenon under study was discussed.