A mathematical model is developed of the steam-stripping process in polymer-solvent-water systems under agitation, describing it in terms of the current theories in the field of polymer-solvent solutions, interphase equilibrium, mass transfer, and agitation. The validity of the model is verified with the results of previous experimental work on the steam stripping of ethylene-propylene-diene monomer rubber slurries in water and is extended to other polymer-solvent-stripping vapor or gas systems, in or not in the presence of water, where spheroidal polymer particles are under homogeneous mixing conditions.