An indicating arrangement for indicating the absence or presence of film in the interior of an X-ray film cassette includes an indicating member movably mounted on one portion of the cassette. Another portion of the cassette which is juxtaposed with the one portion has a recess therein, in which the inner end of the indicating element is received when film is absent from the internal space of the cassette, but which is covered by the film when the same is properly introduced into the internal space of the cassette so that the inner end of the indicating element is prevented from entering this recess. The position of the indicating element can be perceived at the exterior of the one portion of the cassette in a tactile or visual manner. The indicating element may be a discrete element mounted on the cassette, or a one-piece part of a flexible portion of the cassette. In either event, the indicating element is guided in a rigid portion of the cassette so that the position of the indicating element relative to this rigid portion may be ascertained either by touch or by observation.