Nutrition knowledge is an important driver of household dietary diversity that can be improved through access to nutrition information. However, in many rural areas, the formal flow of nutrition information is limited, although social networks could play an important role as an informal source of such information. This paper evaluates the effect of nutrition information networks on household dietary diversity in Nyamira and Kisii counties in Kenya. The paper employs a Poisson regression model on a sample of 462 farmers selected using a multi-stage sampling technique. The results show that the average household dietary diversity of an individual’s network (a proxy for social networks) had a positive and significant effect on the dietary diversity of the individual, implying that social networks have a positive effect on household dietary diversity. Moreover, the average education of an individual’s network, along with household size, wealth status and farm size, had positive significant effects on household dietary diversity. These results imply that farmers’ social networks could be used as a complementary tool for the effective delivery of nutrition education targeting the enhancement of nutritional quality.