First, arbitration is available only to employees in a unionized work force. The American Arbitration Association has encouraged individual-worker arbitration of discrimination claims in nonunion work forces, but the program has not been successful. Second, arbitration under labor agreements will reach employer, but not union, discrimination; and in many situations, the union may have covertly participated in the discrimination. Third, arbitration is limited to actions under the labor agreement, and the grievants must be incumbent employees. Thus, arbitration does not address discrimination in hiring. Fourth, the concept of discrimination is no longer confined to actions directed at particular individuals; it encompasses systemic practices that affect large numbers of people. Arbitration does not provide anything comparable to the class action in the Federal courts; it is confined almost exclusively to individual claims of disparate treatment. Fifth, arbitration does not provide for discovery methods normal to the Federal courts under their rules of civil procedure. Finally, arbitrators do not have the power to enforce their own rules, and some resort to public law, whether or not authorized to do so. Problems of arbitrating sex discrimination cases are considered. Fourteen references are included.