In this paper, we estimate the impact of a farmer field school intervention among small scale farmers in Northers Tanzania. Unlike previous farmer field school evaluations, we go beyond the immediate agricultural impact and estimate the impact of farmer field school participation in the pre-specified development objects, namely poverty alleviation and food security among participating households. We wxploit the implementation design of a gradual project roll-out to establish a quasi-experimental difference-in-difference setup, which can account for potential selection info the project, both at village and household level, despite the lack of baseline data. we find strong positive effects on measures of food security, but we find no effect on the poverty indicators. We investigate possible mechanisms for this and conclude that both reallocation of labor ressources and improved production smoothing among participation households may, in part, lead to this finding.