A mathematical model has been developed to simulate the performance of an integrated extraction-stripping process based on the use of hollow fiber contactors. The model allows one to predict the time-dependent concentration profiles of the two phases involved in an individual extraction or stripping process, or of the three phases involved in an integrated extraction-stripping process (two aqueous phases - feed and stripping - and one organic phase). The model includes as parameters operating conditions such as the initial concentrations, volumes and flowrates, distribution coefficients and overall mass transfer coefficients.