On April 13, 2010, Tajikistan notified WHO of a sharp increase in reported acute flaccid paralysis (AFP) cases. On April 20, the designated WHO regional reference laboratory in Moscow, Russia, identified WPV type 1 (WPV1) in stool specimens from persons with AFP cases; the WPV1 was genetically most closely related to WPV1 isolated in Uttar Pradesh, India, in August 2009. As of November 1, 2010, Tajikistan had reported 458 laboratory-confirmed WPV1 cases from 35 of 61 administrative territories, with paralysis onset dates occuring February 1–July 4. Ninety (20%) patients were aged <1 year, 208 (45%) were aged 1-4 years, 107 (23%) were aged 5-14 years, and 53 (12%) were aged ≥15 years. Early in the outbreak, the majority of cases were in children aged <5 years; after week 20, 78% of cases were in persons aged ≥5 years. Twenty-six (5.7%) patients died; 15 were aged <5 years, eight were aged 5-14 years, and three were aged ≥15 years.