Using a high resolution meteorology-chemistry transport model, simulations were performed to estimate the sensitivity of the model results to nesting. The model results are compared with airplane measurements made during the TRACT field measuring campaign in September, 1992. For the meteorological part of the model the performance is enhanced using one-way nesting in a larger scale model, if the quality of the large scale driving data is sufficient. The sensitivity of the NOx concentration results with respect to nesting of chemical quantities is rather low due to the poor quality of the forcing data. A correct description of the emission rates and the meteorological conditions may be more important. For ozone, the best results can be achieved with either no nesting or a meteorological and chemical nested model simulation, which is again a result of the poor quality of the forcing data.