Food insecurity remains a significant and persistent challenge in sub-Saharan Africa. This has been partly attributed to low food availability associated to subsistence farming and limited access to nutritious foods. In Uganda, food crops such as rice have been highly promoted for commercial production, and many households have allocated resources to production of food-cash crops for the market. In view of the growing population, shrinking land holdings, and questions about the functioning of markets, the underlying motivation for my thesis is to explore whether market-oriented food crop production can sustainably improve rural households’ food security. The thesis provides empirical information on the effects of market-oriented crop production on household food security in a developing country. It reports on a detailed study on the changing farming environment in the context of agricultural production for income, food and nutrition security. This information is important as an input into the process of agricultural production reforms to guide policy decisions based on facts.