A personal air sampler to measure airborne pesticide vapors and aerosols was developed. The sampler consists of a train of collecting and filtering components, including a Swinnex cellulose ester filter cassette, a glass tube containing Chromosorb 102 with a layer of silanized glass wool, and a polyurethane plug. The sampling train is used with a personal sampling pump and a flow rate of 0.2 liter per minute. In laboratory tests, recovery efficiencies for the train were 101, 105, 100, 95, 102, 101, and 98 percent for diazinon (333415), dimethoate (60515), endrin (72208), lindane (58899), methoxychlor (72435), paraoxon (311455), and parathion (56382), respectively. In field tests, results obtained with the sampling train agreed well with those obtained with a midget impinger. The authors conclude that the sampling train is small, easy to carry, unaffected by the wearer's movements, and capable of sampling vapors and aerosols of pesticides at low concentrations.