A film system for flash x‐ray diffraction studies of shock‐compressed samples is described. This system consists of three elements: A blast cassette; a film assembly; and a small shock‐wave generator. The blast cassette contains baffles, slits, and plastic x‐ray windows to prevent shrapnel penetration of the film holder and destruction of the film. High‐speed film is used in conjunction with a ZnS fluorescent screen. Shock pressures of 85–340 kilobars can be generated in typical samples by a miniature explosive lens and booster weighing about 100 g. Tailoring of the sample pressure is achieved through the selection of the base plate and explosive material. We have used this system to obtain diffraction data in the two‐theta range of 15°−50° using Cu and Mo x‐radiation.