Cassava’s high caloric value, as well as its ability to tolerate dry conditions and poor soils, makes it a key food security crop in developing countries, particularly in Africa. It serves as a rich source of carbohydrates, and also contains appreciable amounts of calcium and vitamin C. However, heavy reliance on cassava as the main source of food without additional intake of protein and vitamin-mineral rich food sources can lead to nutrient deficiencies. In particular, vitamin A deficiency is a serious nutritional problem in areas with heavy reliance on cassava as a food. In this chapter, we review the HarvestPlus breeding programme for increasing the nutrient density of cassava. We then consider strategies for promoting the use of pro-vitamin A varieties by farmers and consumers. Finally, we discuss the levels and bioavailability of carotenoids in yellow-fleshed cassava after processing operations.