This paper is addressed primarily to those contemplating purchase of equipment for taking x-ray movies. Its aim is to provide information regarding facilities required, the investment in time and money, information obtained with the technic, frequency of its use, and its influence on the physician's practice. To make x-ray movies, the minimum requirements are an x-ray machine, an image intensifier, a movie camera, circuits to interrupt the beam during film movement, and a light meter or automatic brightness control. Although much information has been obtained with 5-inch image intensifiers, field size under these conditions is severely limited. Only the installation of a machine that permits films to be taken of a field not less than 8 inches in diameter should be considered. Films may be processed by professional processing agencies but, in general, that method has not proved efficient. The films cannot be checked quickly enough and, more important, they are usually developed to a gamma of only 0.6 to 0.7, whereas for x-ray movies development to a gamma of about 1.5 is necessary. Although such forced development results in large grain size, higher fog levels, and less resolution, the high speed and contrast obtained give adequate pictures, requiring a much lower dose of radiation than films developed to a low gamma. For this reason, most workers have processed their own movie films. The simple technic of unrolling the film into a tank of x-ray developer and gently agitating the solution and the film may be used for processing. For short strips, this technic works well, since the film may be fed by hand from one tank to another with the fingers touching only the film edges. Even with short strips, however, many artefacts are created, drying of film becomes difficult, and the results leave much to be desired. Many workers wind the film on a film hanger in absolute darkness, emulsion side out, which permits handling the strip as a unit when passing it from one solution to the other and facilitates drying. However, only about 30 feet of 16-mm. film can be wound on a 14 × 17-inch hanger, and care must be exercised to prevent overlapping of adjacent films. Eventually a processing device will be desired that assures films of excellent quality without the handicaps of the more crude systems. These, however, cost several thousand dollars, are difficult to handle, and do not assure the production of high-quality films unless great care is taken in their use. The dried films are usually first viewed in an editing viewer, of which several types are available. With a viewer that has a shutter, the films can be viewed only at rapid rates if an annoying and fatiguing flicker is to be avoided. In these viewers the light levels are usually adequate. Heat-absorbing glass should be a part of the equipment to prevent burning of films when a single frame is studied.