Free drainage in compressed-air foams were studies experimentally and theoretically. The time evolution of liquid holdup profiles in a 0.2-m-high by 0.29-m-diameter foam column technique was determined at various heights by measuring sonic velocity. A new experimental technique was devised to measure the true drainage rate of surfactant solution leaving the foam column. A drainage model was outlined to predict the discharge rate and evolution of the liquid-fraction profile in aqueous foams. The model led to the formulation of a nonlinear partial differential equation in which the liquid fraction was used explicitly as a dependent variable. The model was applied with one adjustable parameter to simulate drainage in foams made from fluorocarbon surfactants containing mobile plateau border and film walls. The liquid-fraction profiles, drainage rates, and final equilibrium liquid profiles depended strongly on the surface mobility of plateau border and film walls. The liquid-fraction profiles, drainage rates, and final equilibrium liquid profiles depended strongly on the surface mobility of plateau border and film walls; the bubble size; and therefore on the coarsening history in the foam under study. Over longer time periods this model needs to be coupled with inter-bubble gas diffusion to account for coarsening-induced drainage.