Gas/liquid mass transfer characteristics of a membrane contactor with hydrophobic microporous hollow fibers were investigated under laminar flow conditions. Physical absorption of oxygen in a pseudo-plastic non-Newtonian liquid was studied. The experiments were carried out with aqueous solution of sodium carboxymethylcellulose. For comparison, the experiments with water as an absorbent were carried out as well. The influence of physical characteristics of liquids and operating conditions on oxygen absorption was examined. The results show that hydrophobic membrane contactors can be efficiently used for gas absorption in a pseudo-plastic liquid, especially when membrane resistance can be neglected.