The federal and provincial governments of Canada, committed to protecting the environment and public health, consider air pollution to be one of the most important environmental issues for Canadians. The overall objective is to determine the impact of current reduction programs (Canada-USA) on air quality in the province of Quebec and provide the public and decision makers with information on their benefits and on future actions needed to reduce emissions and improve the regional air quality. Both a current atmospheric emission inventory, and the best possible estimate for the future are needed to validate current policies aimed at improving air quality. The first complete AURAMS (A Unified Regional Air-quality Modelling System) version was used for emission reduction scenario applications. AURAMS is a new, size-resolved, chemically characterized, episodic regional particulate-matter (PM) modelling system being developed by the Meteorological Service of Canada for air quality research and management. The meteorological fields needed by the AURAMS model were obtained from the Global Environmental Multiscale model (GEM). Several emission reduction scenarios were run for selected episodes of the summers of 1999 and 2001 based on the current commitments of the governments of Canada and the United States valid for 2010 and 2020. These periods of simulation include exceedances due to local sources as well as exceedances due to long-range transport of pollutants. The simulations consist of reduction of the anthropogenic emissions of smog precursors in the transportation sector, and scenarios included in the Ozone Annex of the Canada-United States Air Quality Accord. This study shows that in Quebec the ozone daily maximum is reduced by 60-70% when running the mobile emission reduction scenarios valid in 2020. When Ozone Annexe commitment valid in 2010 are added to the anticipated mobile emission scenario there is a 70-80% maximum daily ozone reduction observed in Quebec. While the ozone is significantly reduced away from major urban areas the model shows an increase in ozone concentrations in large cities, with NOx emissions reductions. The difference between the scenarios for PM2.5 is very small when transboundary transport is dominant and larger during local episodes.