In most countries, rates of mortality and malnutrition among children continue to decline, but large inequalities between poor and better-off children exist, both between and within countries. These inequalities, which appear to be widening, call into question the strategies for child mortality reduction relied upon to date. We review (1) what is known about the causes of socioeconomic inequalities in child health and where programs aimed at reducing inequalities may be most effectively focused and (2) what is known about the success of actual programs in narrowing these inequalities. We end with lessons learned: the need for better evidence, but most of all for a new approach to improving the health of all children that is evidence based, broad, and multifaceted.