Technical Abstract: Soil fumigants are a special group of pesticides that possess relatively high vapor pressure. Thus a large fraction is in the vapor phase after application in the substrate soil environment. Because of the high vapor pressure, they are also volatile organic compounds with strong potential for air pollution if large emission losses occur. Considerable soil fumigation research has been carried out in the past 15 years because of the phaseout of methyl bromide in the early 1990s. The main research focus has been on documenting the environmental fate and transport of methyl bromide and its potential alternatives using lab and field experiments and computer models. Simulation models are valuable tools for estimating the environmental fate and transport of pesticides and relative importance of pesticide properties, such as vapor pressure, that would affect dominant transport mechanisms in the environment. This article provides a general overview of fundamental physical and chemical principles for modeling the environmental fate and transport of soil fumigants. Discussions are also provided for feasibility assessment of existing pesticide models for simulating soil fumigants and future research needs in modeling soil fumigation.