This paper presents the results of an experimental investigation of the hydrodynamics of a countercurrent packed-bed column exposed to a step change in the liquid flow rate. For the first time in the literature, this paper reports observations of the overshoots of the transient curves of pressure as well as liquid holdup when the change in the liquid rate brings the hydrodynamic regime of the bed close to the flooding line. The experimental technique indicated that column flooding did not appear to occur, even temporarily. The experimental. transient curves for the pressure along the packed section, the total pressure drop across the column, and the liquid holdup are interpreted in terms of a simple three-parameter transfer function. Plots of the magnitude of the overshoot and the instant of its appearance as functions of the gas-to-liquid mass now rate ratio are presented and analyzed. On the basis of these results, the existence of a pressure overshoot is attributed to the extra energy required for redistribution of the gas and liquid flow according to the new prevailing flow regime.