Initial results obtained from the application of X-ray tomography to an operating vapor-liquid contactor indicate that the technology has the potential to provide insight into the underlying hydraulic behavior of a packed column. Experiments were performed with counter-current air-water flows in a 6-in-diameter contactor packed with random packing. Liquid and gas velocities typical of a commercial column were tested. Liquid distribution patterns and holdup values were obtained for three tower elevations. The majority of liquid holdup values obtained from the tomography experiments were within 15% on the parity plot of model versus experiment. The experimental Row patterns for random packing showed a preference for the liquid stream to flow in rivulets.