The Expanded Programme on Immunization (EPI) of the World Health Organization has a global target of reducing measles incidence by 90% and mortality by 95% from pre-EPI levels by 1995. Both developed and developing countries that have given priority to measles control have substantially reduced measles morbidity and mortality, and some have come close to eliminating measles. A variety of vaccination schedules and strategies have been used, which reflect the differing program goals, health services infrastructure, and availability of resources in different countries. Failure to control measles has usually been due to a failure to implement planned strategies adequately. The highest priority in measles control is to assist countries, especially the lowest-income countries, to implement vaccination programs more effectively.