The results of a randomized controlled trial in Tanzania suggest that intermittent preventive treatment in infants (IPTi), delivered through the Expanded Program on Immunization, might be a useful approach to controlling malaria in countries where it is endemic. An international consortium of research collaborations, involving the World Health Organization and United Nation's Children's Fund, is now evaluating IPTi in a range of different settings to generate robust and compelling evidence to guide policy. This review summarizes the available information on IPTi and presents the consortium's approach to determining whether IPTi might be a valuable additional strategy in programs to control malaria.