Vapor pressures are important parameters for environmental fate modeling of chemicals. Vapor pressure curves were obtained for 80 pesticides using an automatized gas saturation method with on-line gas chromatography (GC) analysis. Special consideration was given to a variety of phenomena of importance to the outcome of vapor pressure results: sample contamination by impurities or amorphous phase, solid- to plastic-phase transitions, crystal modifications, and measurements on free acids and on labile pesticides. A vapor pressure correlation method has been developed in the past for halogenated dibenzo-p-dioxins and dibenzofurans and has been used to predict vapor pressures for 29 halogenated dibenzo-p-dioxins and for 55 chlorinated dibenzofurans. The present pesticides were chosen to contain a number of common structure elements with these compounds measured in the past, and this data should be valuable for developing vapor pressure estimation methods.