As new rotavirus vaccines are being introduced in immunization programs, global and national estimates of disease burden, especially rotavirus-associated mortality, are needed to assess the potential health benefits of vaccination and to monitor vaccine impact. We identified 76 studies that were initiated after 1990, lasted at least 1 full year, and examined rotavirus among >100 children hospitalized with diarrhea. The studies were assigned to 5 groups (A-E) with use of World Health Organization classification of countries by child mortality and geography. For each group, the mean rotavirus detection rate was multiplied by diarrhea-related mortality figures from 2004 for countries in that group to yield estimates of rotavirus-associated mortality. Overall, rotavirus accounted for 527,000 deaths (95% confidence interval, 475,000-580,000 deaths) annually or 29% of all deaths due to diarrhea among children <5 years of age. Twenty-three percent of deaths due to rotavirus disease occurred in India, and 6 countries (India, Nigeria, Congo, Ethiopia, China, and Pakistan) accounted for more than one-half of deaths due to rotavirus disease. The high mortality associated with rotavirus disease underscores the need for targeted interventions, such as vaccines. To realize the full life-saving potential of vaccines, it will be vital to ensure that they reach children in countries with high mortality. These baseline figures will allow future assessment of vaccine impact on rotavirus-associated mortality.