An emissions inventory of VOCs, NOx, and CO2 was conducted for three central Florida counties – Orange, Seminole, and Osceola (OSO) – for calendar year 2008. The inventory utilized three programs: MOBILE6, NONROAD2005, and EDMS (Emissions and Dispersion Modeling System) to model on‐road mobile, non‐road mobile, and airport emissions, respectively. Remaining point and area source data was estimated from the Florida Department of Environmental Protection (FDEP) and the U.S. Environmental Protection Agency’s (U.S. EPA) 2008 emissions inventory. The previous OSO emissions inventory was done in 2002 and in the six years between inventories, there have been changes in population, commerce, and pollution control technology in central Florida which have affected the region’s emissions. It is important to model VOC and NOx emissions to determine from where the largest proportions are coming. VOCs and NOx are ozone precursors, and in the presence of heat and sunlight, they react to form ozone (O3). Ozone is regulated by the U.S. Environmental Protection Agency through the FDEP. The current standard is 75 parts per billion (ppb) and Orange County’s average is 71 ppb. A new standard (which will likely be about 65 ppb) is being developed and is scheduled to be announced by July 2011. If OSO goes into non‐attainment, it will need to prepare a contingency plan for how to reduce emissions to submit to the FDEP for approval. The 2008 inventory determined that approximately 71,300 tons of VOCs and 59,000 tons of NOx were emitted that year. The majority of VOCs came from on‐road mobile sources (33%) and area sources (43%), while the majority of NOx came from on‐road mobile sources (64%) and non‐road mobile sources (17%). Other major sources of VOCs included gasoline powered non‐road mobile equipment (lawn and garden equipment), consumer solvents, cooking, and gasoline distribution. With the numbers iii that could be determined for CO2 emissions, on‐road mobile and point sources were responsible for 93%. Of the point source CO2 emissions, almost all of it (87%) came from one large coal‐fired power plant in Orange County.