The Global Polio Eradication Initiative (GPEI) was launched in 1988. By 2006, transmission of indigenous wild poliovirus (WPV) was interrupted in all but four countries (Afghanistan, Pakistan, India, and Nigeria).1 Subsequently, 39 previously polio-free countries experienced outbreaks following importation of WPV, and transmission became reestablished in Angola, Chad, Democratic Republic of the Congo (DRC), and Sudan.2,3 This update summarizes progress toward polio eradication during 2010 and the first quarter of 2011. Worldwide, 1,291 WPV cases were reported in 2010, a 19% decrease from 2009; WPV type 3 (WPV3) cases decreased 92%, but WPV type 1 (WPV1) cases increased 145%. During 2010, 232 (18%) WPV cases were reported from the four polio-endemic countries; 159 (12%) cases were reported in Angola, Chad, and DRC; and 900 (70%) cases were reported in 13 countries, including two countries with outbreaks continuing from 2009 and 11 with new importations. During 2010, WPV cases in India and Nigeria decreased ≥94% compared with 2009. Outbreaks in Tajikistan and the Republic of the Congo (Congo) accounted for two thirds of cases (842) in 2010.4,5 All new outbreaks in 11 polio-free countries in 2010 were stopped or were on track to being stopped within 6 months of outbreak confirmation. During January—March 2011, substantially more WPV cases occurred in Chad, DRC, and Pakistan than during the same period of 2010. To further progress toward polio eradication and achieve the 2012 target of ending all WPV transmission, significant increases in resources and political commitment are needed.