Polyetheretherketone (PEEK) resin has been produced in commercial quantities for over 20 years. While it is used widely in demanding injection-molded and machined applications, its use as a film in thermoforming applications is only now being discovered, and PEEK films and sheets have become more available in the marketplace during the past few years. This presentation reviews some of the basics of PEEK film properties, in particular of the two crystalline forms that are commercially available; typical processing conditions and equipment that have been used to thermoform parts ranging in thickness from 6 to 1000 microns; and some details of current application areas for thermoformed PEEK parts.