INTRODUCTION: Recently developed rotavirus vaccines have the potential to reduce diarrhea mortality in children in developing countries. Available data to date do not indicate risk of intussusception with these new vaccines. To avoid a potential unanticipated risk post-licensure, it is recommended that rotavirus immunization be initiated before 12 weeks of age when background intussusception rates are low. This policy could exclude a substantial number of children from vaccination, especially in developing countries where delays in vaccination are common. METHODS: We conducted a scenario analysis to assess the potential benefits of mortality reduction from rotavirus versus the risk of fatal intussusception when the first dose of the vaccine is strictly administered by 12 weeks of age compared with a free strategy with vaccine administered before 1 year of age using data on rotavirus disease, vaccine safety and efficacy, and current diphtheria-tetanus-pertussis vaccination rates, and by incorporating hypothetical risks of intussusception. RESULTS: In developing countries, assuming vaccine efficacy of 50% and 75% for doses 1 and 2, respectively, and a hypothetical sixfold and threefold increased relative risk of intussusception within 7 days of doses 1 and 2, respectively, initiating rotavirus immunization before 12 weeks of age would prevent 194,564 of the 517,959 annual rotavirus-associated deaths among children <5 years, while potentially resulting in 1106 fatal intussusception events. Administration of the first dose to infants up to 1 year of age would prevent an additional 54,087 rotavirus-associated deaths (total=248,651) while potentially resulting in an additional 1226 intussusception deaths (total=2332). CONCLUSION: In developing countries, the additional lives saved by broadening the age restrictions for initiation of rotavirus vaccination would far outnumber the hypothetical excess intussusception deaths that would accompany such an approach.