Using survey-data from Peru, this paper evaluates the impact of a pilot farmer-field-school (FFS) program on farmers' knowledge of integrated pest management (IPM) practices related to potato cultivation. We use both regression analysis controlling for participation and a propensity score matching approach to create a comparison group similar to the FFS participants in observable characteristics. Results are robust across the two approaches as well as with different matching methods. We find that farmers who participate in the program have significantly more knowledge about IPM practices than those in the non-participant comparison group. We also find that improved knowledge about IPM practices has a significant impact on productivity in potato production.