A numerical model of bioventing plants equipped with horizontally installed venting wells is developed. It is based on the equations for fluid flows in porous media. These equations are discretized according to the finite-volume method. Different boundary conditions are used in order to describe the influence of injection, extraction and passive wells in the domain under investigation. The numerical model is verified by laboratory- scale experiments, which are also described shortly. The proposed model permits a reasonable description of the flow field of pressurized air between the injection and extraction wells of a soil bioventing unit, even if the porous media are heterogeneous and the permeability of the soil varies. Hints for the calculation of analogous bioventing installations are deduced from the comparison of the numerical with experimental data.