This paper focuses on Integrated Pest Management (IPM) Programs in Nong Khae and Nong Done districts in Sarabri province, Central Thailand. This program started in 2003 to introduce IPM technology to local rice farmers for the purpose of “reduction of pesticides use” and “reduction of production cost.” The investigations for the IPM technology adoption among farmers and its impacts were carried out by interviewing to 50 rice farmers in both districts. In the IPM program, Farmer Field School (FFS) played the important role to increase farmers' skills and lowering pesticide use in rice. No characteristic (age, educational background, field area etc.) differences between IPM and non-IPM farmers imply that every rice farmers can conduct IPM in reality. IPM farmers, most of them graduated from FFS, succeeded in about 57.5% reduction of pesticide use, and applied pesticide about 1.43 times in a crop season while non-IPM farmers applied about 2.6 times. This lowering pesticide uses contributed to reduction of production costs and risks of health and environment. However, the outcomes by IPM adoption will be much greater if the population of IPM farmers in the districts increases; network externality. For this, it is necessary to consider the process from the prevalence of IPM technology by FFS to the diffusion of IPM technology through FFS participants to nonparticipants. This activity should be enhanced by continuing FFS approach in the districts, identifying health and environmental impacts of IPM practices, and opening IPM rice markets. JEL Classification: R58, Q18, Q57