Smoke is a mixture of toxic gases and suspended particulate matter of solids and liquids that evolves from a fire of flammable materials. This article presents real-time consequence modeling to track the concentration of individual species in smoke as well as its soot deposition. In the modeling process presented, the burning rate or vapor mass is fed into a combustion model in which the combustion of products has been identified and quantified along with the temperature of the fire. The output of the combustion model is the smoke that will be dispersed into the ambient. The fire geometry, which depends on the type of fire (e. g., pool or flare), is identified. A dispersion model with the capability of determining particulate deposition is then used for tracking the smoke plume. The combustion model provides the composition of the toxic species present in the smoke: carbon monoxide, halogen acids, organic and inorganic irritants, and soot, and their quantities as the air-to fuel ratio is changed. The end product is an excellent what-if analysis tool for responders. For example, it provides the ability to determine whether to ignite or when to ignite a flammable, toxic release by comparing their consequences. (C) 2011 American Institute of Chemical Engineers Process Saf Prog 30: 168-177, 2011