A chemical mechanism, including the relevant reactions leading to the production of ozone and other photochemical oxidants, has been implemented in the MATCH regional tracer transport/chemistry/deposition model. The aim has been to develop a model platform that can be used as a basis for a range of regional scale studies involving atmospheric chemistry, including assessment of the importance of different sources of pollutants to the levels of photochemical oxidants and air pollutant forecasting. Meteorological input data to the model were taken from archived output from the operational version of HIRLAM at SMHI. Evaluation of model calculations over Europe for a six month period in 1994 for a range of chemical components show good results considering known sources of error and uncertainties in input data and model formulation. With limited further work the system is sufficiently good to be applied for scenario studies and for regional scale air pollutant forecasts.