In 2000, countries represented by the World Health Organization (WHO) Regional Office for Africa established a goal to reduce, by the end of 2005, measles mortality to 50% of the 506,000 deaths from measles estimated in 1999. Strategies adopted included strengthening routine vaccination, providing a second opportunity for measles vaccination through supplemental immunization activities (SIAs), monitoring disease trends, and improving measles case management. In Kenya, an east African country with a population estimated at 33.4 million in 2005, the Kenya Expanded Programme on Immunization (KEPI) in the Ministry of Health began implementing these strategies in 2002 with a wide age range catch-up SIA and reduced the number of reported measles cases by >99%, from 11,304 in 2001 to 20 in 2004. A follow-up SIA, initially scheduled for July 2005, was postponed to 2006 to include concurrent distribution of long-lasting insecticide-treated bednets (LLINs). This report documents progress made in reducing measles morbidity and mortality in Kenya and describes the consequences of a large measles outbreak, beginning in September 2005, on the integrated measles follow-up SIA.