Maternal and child undernutrition and micronutrient deficiencies affect approximately half of the world's population. These conditions include intrauterine growth restriction (IUGR), low birth weight, protein-energy malnutrition, chronic energy deficit of women, and micronutrient deficiencies. Although the rates of stunting or chronic protein-energy malnutrition are increasing in Africa, the absolute numbers of stunted children are much higher in Asia. The four common micronutrient deficiencies include those of iron, iodine, vitamin A, and zinc. All these conditions are responsible directly or indirectly for more than 50% of all under-5 deaths globally. According to more recent estimates, IUGR, stunting and severe wasting are responsible for one third of under-5 mortality. About 12% of deaths among under-5 children are attributed to the deficiency of the four common micronutrients. Despite tremendous progress in different disciplines and unprecedented improvement with many health indicators, persistently high undernutrition rates are a shame to the society. Human development is not possible without taking care to control undernutrition and micronutrient deficiencies. Poverty, food insecurity, ignorance, lack of appropriate infant and young child feeding practices, heavy burden of infectious illnesses, and poor hygiene and sanitation are factors responsible for the high levels of maternal and child undernutrition in developing countries. These factors can be controlled or removed by scaling up direct nutrition interventions and eliminating the root conditions including female illiteracy, lack of livelihoods, lack of women's empowerment, and poor hygiene and sanitation.