How have charter schools in Wisconsin performed relative to traditional public schools? Two analyses provide an answer: First, a comparison of achievement test scores for students in Milwaukee charter and traditional schools from 1998 to 2002 for grades 3 through 10 finds a relative advantage for charter school students using fixed effects and first difference specifications. Second, a methodological approach new to the debate over performance in choice schools assesses schoollevel standardized tests in the fourth and eighth grades for 2000–01 and 2001–02. The results for fourth grade are generally favorable for charter schools, those for eighth grade are mixed. Overall, the results from these two analyses suggest that charter schools in Wisconsin are performing somewhat better than the traditional public schools from which they draw students. © 2007 by the Association for Public Policy Analysis and Management