The effects of gas and liquid flow rates on gas-phase mass transfer from a turbulent gas stream into a laminar falling liquid film in wetted-wall columns with cocurrent and countercurrent gasliquid flow were studied. Numerical solutions were obtained for the average gas-phase Sherwood number as functions of the gas-phase Reynolds number based on the gas velocity relative to the liquid surface, the dimensionless interfacial gas velocity, the gas-phase Schmidt number and the dimensionless column height. Experiments were carried out on the absorption of ammonia into aqueous sulfuric acid solution, using two columns of different dimensions. The agreement between experimental and predicted effects of both gas and liquid flow rates on gas-phase mass transfer rate was found to be fairly good.