A resurgence of interest in inner speech as a core feature of human experience has not yet coincided with methodological progress in the empirical study of the phenomenon. The present article reports the development and psychometric validation of a novel instrument, the Varieties of Inner Speech Questionnaire (VISQ), designed to assess the phenomenological properties of inner speech along dimensions of dialogicality, condensed/expanded quality, evaluative/motivational nature, and the extent to which inner speech incorporates other people's voices. In response to findings that some forms of psychopathology may relate to inner speech, anxiety, depression, and proneness to auditory and visual hallucinations were also assessed. Anxiety, but not depression, was found to be uniquely positively related to both evaluative/motivational inner speech and the presence of other voices in inner speech. Only dialogic inner speech predicted auditory hallucination-proneness, with no inner speech variables predicting levels of visual hallucinations/disturbances. Directions for future research are discussed.