Abstract: A process for producing almost perfect graphite films and fibers at lower graphization temperatures wherein a film or fiber of a polymer selected from a defined group is subjected to a preliminary heat treatment at a temperature of 400.degree. to 700.degree. C., under tension, in vacuo or in an inert gas, and then heat treating the film or fiber at a temperature of at least 1600.degree. C. in vacuo or in an inert gas, to graphitize the film or fiber. The process can be modified to produce graphite films having excellent electric conductivity and mechanical properties, by heat treating a polymer selected from a second defined group at a temperature of at least 1800.degree. C. in vacuo or in an inert gas, impregnating the film with a binder component, and then heat treating the impregnated film at a temperature of not more than 1400.degree. C.