<b><i>Background:</i></b> Hysteria in its most severe expression may reach psychotic manifestations. Such symptomatology has been occasionally described by various authors starting from the 19th century and defined as “hysterical psychosis” (HP) by Hollender and Hirsch in 1964. Currently, diagnostic psychiatric manuals such as DSM and ICD do not include the diagnosis of HP, although this term is commonly used in clinical practice. This raises a well-known problem with case definition due to an inconsistent use of terminology. <b><i>Summary:</i></b> Here, we propose a review of the literature that aims to highlight the clinical features of HP endorsed by the majority of authors, such as histrionic premorbid personality, acute reactive onset, short duration, altered state of consciousness, unstable delusions, typical hallucinations, labile mood, lack of flat affect. In the discussion, we focus on the differential diagnosis between HP and other diagnoses such as brief psychosis and schizophrenia, trying to point out aspects of distinction and continuity. <b><i>Key Messages:</i></b> The debate about this nosographic entity still remains a huge dilemma and needs further contributions.