The purpose of this paper is to examine, from a Constitutional perspective, the bases on which ability grouping and tracking might be challenged as barriers to equal educational opportunity. Findings from educational research on ability grouping, commentary from law review journals, and the texts of cases themselves are included as a part of the inquiry into the direction such legal challenges might take. Three approaches are followed in the analyses of the legal literature. First, those concepts likely to influence both the character of a legal challenge to ability grouping and the direction of the court's responses to such a challenge are identified. Second, those cases in which tracking has already been considered by the courts are examined to determine legal precedents for future court action. Third, cases which might be considered analogous--those dealing with related issues--are reviewed to identify legal approaches which might be adopted in a challenge to ability grouping and tracking. (Author)