In a key opinion this week, the United States Court of Appeals for the Ninth Circuit clarified the standards that district courts are to apply in determining whether to grant class action status to a case. In Dukes v. Wal-Mart Stores, Inc., No. 04-16688 (9th Cir. Apr. 26, 2010), the court, in a 6-5 decision, affirmed in part a decision by the District Court for the Northern District of California to certify a class of hundreds of thousands of female Wal-Mart employees allegedly subjected to gender discrimination. The decision reaffirms that district courts must undertake a rigorous analysis at the class certification stage to ensure that the requirements of Rule 23 of the Federal Rules of Civil Procedure are met, while simultaneously opening the door to a potential increase in large-scale class actions.