Background: Climate change in Sub-Saharan Africa has had a negative impact on agricultural production leading to food insecurity. Climate-smart agricultural (CSA) practices have the potential to reverse this trend because of its triple potential benefits of improved productivity and high income, reduction or removal of greenhouse gases and improved household food security. Hence, we empirically find the determinants of choice and the effect of CSAs on household food security among smallholder farmers in Kenya. Methods: Primary data were collected in Teso North Sub-county, Busia County of Kenya, among smallholder farmers. CSA practices used by farmers were grouped by principal component analysis and linked to food security by multinomial endogenous switching regression model. Results: With the application of principal component analysis, we clustered the CSA practices into 4 components: crop management, field management, farm risk reduction and soil management practices. We find that the greatest effect of CSA adoption by smallholder farmers on food security is when they use a larger package that contains all the four categories of practices. Adopters of this package were 56.83% more food secure in terms of HFCS and 25.44% in terms of HDDS. This package mitigates upon the impacts of climate change as well as enhancing nutrient availability in the soils for higher productivity. Further, adoption of this package was positively influenced by gender of the household head, farm size and value of productive farm assets. Conclusions: CSAs have the potential to alleviate food insecurity among smallholder farmers if used in combinations and to a larger extend. To enhance adoption, land fragmentation should be discouraged through civic education and provision of alternative income-generating activities for farmers to benefit when practiced on relatively bigger land. Farmers should be sensitized on the need to invest in farm productive assets in order to absorb the risks of climate change while enhancing adoption of CSA practices.