In this paper, we investigate the impact of the Farmer Field School (FFS) intervention among small-scale tomato farmers in Beijing. Using data collected by face-to face-interview from 358 households on 426 planting plots in 2009, we evaluate the yield effect and find evidence of positive impact. We then examine the determining factors of farmers’ FFS attendance using the zero-inflated Poisson model. We find evidence of the positive impact of the FFS program on male participants but no impact on female participants. We find that some factors, such as being the household head, wealth level and land size affect both FFS participation decisions and attendance decisions, whereas other factors may affect only one decision but not the other. The results suggest that FFS is a useful way to increase production of farmers in Beijing and that the approach is especially effective for male and wealthy producers with smaller farm sizes and higher literacy.