Smallholder farmers and pastoralists produce the largest proportion of food consumed in sub-Saharan Africa. However, they remain among the food insecure populations. This paper explores the food (in)security among smallholder farmers and pastoralists using a sample of 175 households in three agro-food value chains of wheat, dairy, and beef in the north-west Mt. Kenya region. The study seeks to answer if a farmer’s participation in a particular agro-food value chain determines his/her food security situation. We use the Household Food Insecurity Access Scale (HFIAS) and two Poisson regression models, parsimonious and full, to assess the household food security status and determinants of food security among the smallholder farmers and pastoralists. The results show that 61% of the households were either mildly, moderately, or severely food insecure. Households in the beef value chain experienced relatively higher incidences of food insecurity compared to households in the wheat and dairy value chains. The HFIAS scores revealed a wide gap between households with minimum and maximum score. Household size, income and income-related variables (ability to save and borrow to meet family needs), transport assets, membership in farmers’ associations, and household energy were significant in determining household food security, while access to credit and to extension services was not. Strategies that focus on boosting smallholder farmers’ incomes, building strong and resilient farmers associations to improve inclusive and equitable value chains have the potential to get smallholder farmers out of recurrent food insecurity.