Natural enemies marketed for use in the management of pest insects and mites have considerable commercial potential. However, their market value is small compared with that of conventional pesticides, and the natural enemies are produced primarily by small businesses that have limited capital. Thus, special care should be taken to ensure that undue regulation does not become a barrier to the development and use of these desirable pest control agents. Although multicellular natural enemies are included under the definition of “pesticide,” as given in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) administered by the U.S. Environmental Protection Agency (EPA), they have been exempted by EPA from regulation under FIFRA on the basis that they are adequately regulated by other federal agencies. Natural enemies are currently regulated at the federal level using procedures associated with the Plant Quarantine Act and the Federal Plant Pest Act, primarily through the issuance of permits by the Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture (USDA). These permits authorize and facilitate importation as well as interstate shipment and release of the organisms involved. Innovations in procedures for issuing permits to import, contain, move, and release organisms in the United States initiated in 1995 by APHIS provide a framework for simplifying the permitting procedures for well-known natural enemies used for biological pest control. The modified procedures have resulted in the rapid issuance of multiyear permits for natural enemies that appear on lists of species approved for “expedited” permitting. These procedures have the potential for providing an appropriate level of regulatory oversight for marketed natural enemies without unnecessary procedures and delays. An advance notice of proposed rulemaking that has been issued by APHIS may result in revised procedures.