Biomass burning in the tropics is set intentionally during dry season each year to destroy agricultural waste and clear land for human expansion. These burning activities cause pollution including atmospheric particulates and trace gases which are harmful to human health. Measurements from the Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) from October 2004 – November 2008 are used to evaluate the effects of biomass burning on tropical tropospheric ozone in the context of the Global Modeling Initiative (GMI) chemical transport model. The impact of biomass burning on ozone is significant within and near the burning regions with increases of ~10– 25% in tropospheric column ozone relative to average background concentrations. Globally the model indicates increases of ~4 –5% in ozone, ~7 – 9% in NOx (NO + NO2), and ~30– 40% in CO.