The transport of p-nitrophenol (PNP) through an agitated bulk liquid membrane (ABLM) was investigated. A kinetic model of two consecutive irreversible first order reactions was applied in order to describe pertraction. The influence of PNP concentration in the feed solution, NaOH concentration in the stripping phase, and the type of solvent on the transport parameters (k(f)', k(s)', t(max), R-LM(max), J(max)) was studied. To describe transport kinetics, the apparent mass transfer coefficient (k' [cm/s]) as a parameter independent of volume and a membrane area was proposed. The results indicated that pertraction efficiency decreases in the series: benzene > toluene > p-xylene. In the investigated range of concentrations, the influence of the feed phase concentration (PNP) on pertraction efficiency is much higher than the stripping phase concentration (NaOH). It was also found that pertraction is controlled by PNP diffusion and sorption (extraction) at the feed/liquid membrane interface. The average value for the overall mass transfer coefficient is equal to 3.564(+/- 0.047) x 10(-4) cm/s which is characteristic for the studied system.