Mutual diffusion coefficients for an acrylic adhesive-methyl propyl ketone system were measured at 313.15 K, 323.15 K and 333.15 K by using a sorption and desorption method, and are predicted by the free volume theory of Duda el al. which was modified by Iwai et al. The six model parameters out of eight required to predict the mutual diffusion coefficients are estimated by adopting a previous method from the physical properties of methyl propyl ketone. The predicted values are in fairly good agreement with the experimental results.