A numerical model has been developed for the study of axial mass transfer in gas-liquid Taylor flow at low Bodenstein numbers. The model assumes well mixed liquid slugs of uniform concentration and liquid films around the bubbles that can be adequately described by a one-dimensional convection-diffusion equation. A finite volume method was used for its solution. It was found that the model is suitable for Ca < 10(-3), Bo < 500 and L-s < 16. In addition for Bo > 10 it could be approximated by a simple analytical expression. The results showed that axial mixing is low and increases with increasing film thickness as well as increasing bubble and slug lengths. (C) 2004 Elsevier B.V. All rights reserved.