Publisher Summary This chapter focuses on pesticide absorption with an expanded focus on dermal absorption as workers involved in pesticide manufacturing, formulation, or application and harvesting of treated crops are more likely to be exposed to these chemicals via the skin. Absorption is the translocation of the pesticide from an external source of exposure to the bloodstream. Human exposure to pesticides can result in absorption by passive diffusion across the epithelium layers of the skin and/or the gastrointestinal tract. Once in the blood, the chemical is distributed through the body and delivered to tissues, where it may leave the blood and enter the cells of the tissue or it may remain in the blood and simply pass through the tissue. As occupational exposure via the skin is the most likely source and route for human exposure, this chapter focused on the main physicochemical, biological, and environmental factors that could significantly influence systemic absorption following dermal exposure to examples of pesticides with diverse physicochemical properties. The future of risk assessment of pesticides will depend heavily on the quality of these permeability models and their flexibility to predict dermal and oral absorption in a variety of human exposure scenarios at home and work.