In order to support as critical input to air quality forecasting task during Commonwealth Games (CWG) – 2010 in mega city Delhi, we have developed a high resolution emission inventory of major atmospheric pollutants. For the same, inventories of ozone precursors like NOx and CO are developed over a domain of 70 km × 65 km with a grid of 1.67 km × 1.67 km resolution covering Delhi and surrounding region using Geographical Information System (GIS) technique for base year 2010. All possible source of emission like transport, thermal power plants, industries, residential, slum cooking and commercial cooking are taken into account for the first time. It has been found that total emissions of NOx and CO over the study area are found to be 255 and 703 Gg/yr for 2010 respectively. The spatial distributions of major hot spots are discussed with possible dominant sources at particular regions. The present inventory will help to improve the modeling study over mega city, Delhi and its surrounding regions.