Abstract: Mass transfer in the falling film of laminar non-Newtonian liquid was studied experimentally. A wetted column was used to measure the rate of absorption of carbon dioxide in aqueous polymer solutions, the rheological behavior of which is well characterized by the power-law model. The experimental results showed that the exact solution of the differential equation of diffusion, which considers the velocity distribution in the falling film of non-Newtonian power-law fluids, are proper. It was found that for pseudoplastic fluids it is adequate to use the dimensionless length Z<0.1 as the criterion for the applicability of the penetration theory, which the exact expressions would be applicable to the entire range of the dimensionless length.