The aim of this work was to experimentally study the acetone absorption in water by means of capillary membrane contactor. A "resistance in series" model was used to describe the rate of mass transfer. The experiments were designed in batch system for laminar and transient flow region. Results were approximated by mathematical model based on mass balance equations. The kinetic model enables to calculate two parameters: the equilibrium constant and mass transfer coefficient and takes into account the gas concentration profile along the equipment. The Wilson method was used to calculate membrane mass transfer resistance. Eight series of experiments for two types of modules and various flow arrangements were made for accurate approximation of membrane resistance and gas/liquid mass transfer coefficients. The results follow previous observations on advantages of the absorption process in the membrane contactors, additionally the process stability and a high performance compared to conventional absorption equipment were confirmed. However, there is still lack of appropriate description of shell side mass transfer in case of randomly packed polymeric fibers. A new correlation is proposed on the bases of conducted experiments. (C) 2011 Elsevier BM. All rights reserved.