Under-nutrition and lack of micro-nutrients continues to remain a challenge in developing countries. As the undernourished are largely smallholder farmers, it is predominantly perceived that farm diversification and mixed crop-livestock agricultural systems can help alleviate this problem. But empirical evidence in this context is limited. Hence, this work examines whether farm production diversity as well as mixed crop-livestock farming lead to dietary diversity among smallholder farmers in Laos, using a two year panel data. Results from the fixed effects regression indicate that although farm production diversity does lead to a higher dietary diversity; the effect diminishes with continued diversification. The counterfactual analysis from the endogenous switching regression shows that following mixed crop-livestock farming system reduces household dietary diversity. We further find that markets play a significant role in enhancing the dietary diversity of the specialized farmers.