In recent years an increase of interest concerning the altered states of consciousness was observed. In particular literature provided a wide amount of contribution about the scales for measurement of level of responsivity. Our aim is to describe the principale scales used in diagnosis of Disorder of Consciousness (DOC) trying to illustrate administation procedures, specifically assessed aspects, modality of stimulation, reliability, and validity. We divided them in four main different groups: the first one in which descriptive scales are included, that is those scales basically used after a clinical observation; the second group which concerns scales requiring defined stimulation sets; in the third group we considered the scale which refer to diagnostic criteria stated by the Aspen Work Group (Giacino et al., 2002); whilst in the fourth group we describe a battery aimed to assess patients with severe cognitive deficits which are not yet evaluable with neuropsychological tests