Micronutrient deficiencies or ‘hidden hunger’ resulting from unbalanced diets based on starchy staple crops are prevalent among the population of sub-Saharan Africa. This review discusses the effectiveness of agronomic biofortification - the application of mineral micronutrient fertilizers to soils or plant leaves to increase micronutrient contents in edible parts of crops – and it's potential to fight hidden hunger. There is evidence that agronomic biofortification can increase yields and the nutritional quality of staple crops, but there is a lack of direct evidence that this leads to improved human health. Micronutrient fertilization is most effective in combination with NPK, organic fertilizers and improved crop varieties, highlighting the importance of integrated soil fertility management. Agronomic biofortification provides an immediate and effective route to enhancing micronutrient concentrations in edible crop products, although genetic biofortification may be more cost effective in the long run.