Since attorneys general gathered in Missouri in 1907 to discuss a consolidated approach to antitrust concerns related to Standard Oil, multistate actions have been a powerful tool available to attorneys general. Multistate litigation includes any coordinated litigation among two or more attorneys general against the same defendants. The most well-known multistate litigation settlement is the Master Settlement Agreement between the attorneys general and several large tobacco companies.

NAAG maintains the Multistate Antitrust Litigation Database. The database is an ongoing effort to convey what states do and responds to requests from antitrust academics and practitioners for a single authoritative and comprehensive source of state antitrust enforcement information.  The database focuses on criminal and civil cases from 1990 to the present.

NAAG also maintains a collection of multistate amicus briefs submitted by attorneys general in antitrust cases.