Commentary and analysis of the Class Action Fairness Act of 2005, enacted on February 28, 2005. This article discusses the Act’s creation of new federal original jurisdiction for class actions where the plaintiffs can show that the proposed class consists of more than 100 claimants, there is minimal diversity of citizenship among the parties, and the amount in controversy exceeds $5 million. 28 U.S.C. § 1332(d). Act also includes provisions for mandatory jurisdiction over class actions, as well as discretionary exceptions and exclusions for types of state local controversies. The article discusses the new removal provision for state class actions in 238 U.S.C. § 1453, and provisions for interlocutory appeal of removal actions. In additional the article explores CAFA’s provisions for so-called mass action cases in state court, coupon settlements, and attorney fees. The article assesses possible problems of interpretation and application of the statute’s new provisions. In a companion piece, the authors explore the possible implications of CAFA for mass tort litigation in state and federal courts.