The aim of this review is to find data about the outcome of schizophreniform disorder. As different definitions of schizophreniform disorder were found in the literature, it was not surprising that data on its outcome, and on the relationship of schizophreniform disorder to schizophrenia and to mood disorders (as this relationship is linked to outcome), were often different and opposite. Its classic description of an acute onset psychotic episode with mood instability and a relatively brief duration should be the focus of future studies. Current studies, apart from a small number, lump together different (and probably distinct) subtypes of schizophreniform disorder (one with good prognostic features, and one without good prognostic features, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition). Studies of mixed samples led to different results, probably depending on the relative prevalence of one subtype over the other one. The few studies on schizophreniform disorder with good prognostic features found more often an episodic, recurrent course, and a family history of mood disorders. These features link this schizophreniform disorder subtype more to mood disorders than to schizophrenia. If confirmed by future studies, these preliminary findings can have very important treatment implications, given the very different treatment strategies in mood disorders compared with schizophrenia.