IntroductionHunger and malnutrition remain serious issues in developing countries, particularly in rural regions. Increased market participation of smallholder farmers can result in improved livelihood and nutrition outcomes. However, smallholder farmers encounter several obstacles that hinder their ability to participate in the market. As a result, the objective of this study is to investigate the factors that influence market participation and its impact on household nutrition security.MethodsThe study relied on secondary data gathered from a sample size of 1,520 people. About 389 of smallholder farmers participated in the market.Results and DiscussionThe results from Food Consumption Score (FSC) cut-off points showed that in the overall sample households, 54% were within the acceptable food consumption diets (>35), while 30 and 16% were in the borderline (21.5–35) and poor diets (0–21), respectively. According to the Household Dietary Diversity Score (HDDS) findings, 57% of smallholder farmers in the total population sample consumed highly diverse diets (consisting of at least six food groups), while 25 and 18% of smallholder farmers consumed diets with medium dietary diversity (consisting of 4–5 food groups) and low dietary diversity (consisting of at most three food groups), respectively. The results from marginal analysis showed that gender of household head, receiving social grants and higher wealth index had a positive impact on market participation. The results from Poisson endogenous treatment effect model showed that household size, ownership of livestock, social grant, wealth index, access to market information, and involvement in crop production had a positive and statistically significant impact on household nutrition security. On the other hand, agricultural assistance showed a negative and significant impact on household nutrition security.Conclusion and RecommendationsIt can be concluded that an improvement in agricultural assistance can improve the household nutrition security status. The improvement of agricultural assistance is more associated with improvement of extension services, which can lead to more production of diverse crops and more market participation. Health extension workers need to do more nutrition programs and workshops in rural areas. These programs and workshops will be intended on providing nutrition education, which will create awareness to smallholder farmers on diverse and balanced food items they should produce, sell, and consume.