The study assessed the impact of sustainably adopting Sustainable Agricultural Practices (SAPs) on household poverty, food and nutrition security. Different scholars have assessed the impact of adopting agricultural practices including SAPs on livelihoods of smallholder farmers. Nonetheless, through the focus on one-time survey season adoption decisions, the findings on potential impacts of SAPs which are aimed at informing policy direction remain inconclusive. The current study introduced the concept of sustainability in the adoption of SAPs to iron out inconsistences in the adoption of such practices, and hence assessed whether farmers were better off in terms of poverty status, food and nutrition security than their counterparts. Through the use of Selectivity-corrected Endogenous Switching Regression models on a sample of 2100 farmers, the study notes that gender of household head, education of the household head, natural log of household annual income, Tropical Livestock Units (TLU), farmer membership of farmer clubs and village savings and loan groups significantly influenced the probability of smallholder farmers sustaining their adoption of Sustainable Agricultural Practices. Furthermore, the study notes tangible evidence of an improvement in household food and nutrition security by farmers sustainably adopting SAPs as compared to their counterparts. Nevertheless, no evidence exists that sustained adoption of the practices would alleviate poverty of smallholder farming households. The study recommends the development of an agricultural productivity enhancement program that cuts across the gender divide and social barriers of smallholder farmers, further focusing on promoting farmer clubs and village savings groups to ensure sustained adoption of agricultural practices. Such a program should employ a clear targeting strategy with an aim of targeting food insecure as opposed to poor households in order to eradicate hunger.