This paper examines the effect of labor organization on integrated pest management (IPM), using cross section data collected from a participatory farming system survey of 157 durian growers in Chanthaburi, Thailand, in 2005. In contrast to many studies of IPM adoption, this work uses the form of farm labor organization as an endogenous factor for identifying the rate of IPM adoption among durian growers. The instrumental variables method was employed to econometrically relate a set of alleged variables as instruments of labor organization to the rate of IPM adoption. Results show that, among others, farms employing hired labor have a significantly lower adoption rate of IPM.