About half the states in the U.S., either by legislative or administrative action, have moved toward the imposition of statewide performance standards in their elementary and secondary schools. Typically these standards pertain to the basic skills--reading, mathematical computation, and written and oral expression. Almost all of these programs have been instituted since 1974. Students and their parents will be the primary parties with interest in challinging the existence and implementation, or the non-existence, of performance standards. Judicial decisions suggest that the courts may not be favorably disposed to challenges to the exercise of discretion by school authorities. Plaintiffs challenging the existence and implementation of minimum pupil performance standards are most likely to base their legal arguments on the equal protection and due process clauses of the federal and state constitutions, education clauses of state constitutions, general statutory provisions, and common law negligence theories. Plaintiffs are likely to be confronted with a heavy burden of persuasion. Either the per se illegality or the specifics of existing programs may be challenged. The concept of equal educational opportunity has many definitions. Some relate to pupil performance, while others relate to the opportunity to be exposed to certain educational services. A number of court decisions are discussed. (CTM)