This case study explores the United Kingdom's (UK's) approach to improving low-performing schools and presents lessons learned that could be applied in other countries. The study: (1) Gives an overview of the overall structure of UK schools; (2) Provides a context for the country's school-improvement efforts; (3) Reviews the different types of evidence used to inform school improvement strategies and how those strategies have evolved over time; and (4) Describes how poor performance was improved in one school. This is one of four case studies developed in mid-2009 for the U.S. Department of Education that focus on how countries other than the United States have been addressing the challenge of turning around their low-performing schools. The other three case studies focus on Australia, Canada, and New Zealand. (Contains 3 exhibits and 7 footnotes.)