In the years since the U.S. Supreme Court handed down Brown v. Board of Education (1954), most discussions of the case have focused on whether it was effective in promoting lasting equality of opportunity in the public schools. Although this profoundly important question dominates retrospectives on Brown, another unresolved controversy relates to whether the ruling has altered in any fundamental way the role of social science evidence in constitutional litigation. More than 50 years later, substantial disagreement persists about whether this kind of research has played or should play any important role in the jurisprudence of race. Today, social scientists face increasing doubts about their neutrality and objectivity, struggle to be heard in a marketplace of ideas increasingly flooded with information of questionable quality, and encounter growing resistance to the notion that expertise provides a proper foundation for legal decisionmaking. For those who still believe that social science has a role to play in advancing racial justice, the strategy used in Brown can no longer be taken for granted. The time is ripe to reassess what counts as knowledge so that social science is not increasingly marginalized in courts of law.