This article discusses conceptual issues relevant to the prospective diagnosis of the schizophrenic prodrome. Recent efforts to diagnose these patients with operational criteria based on current symptoms are reviewed. Symptomatic patients so identified appear to be treatment-seeking and to have mild cognitive impairments. In addition to being currently symptomatic, these patients are imminently at risk for progression of illness and development of schizophrenia. Data from three international centers suggest that this risk is approximately 40% over the next year of follow-up if untreated. The implications of the reviewed data for the appropriateness of the term “prodromal” and for treatment/prevention research for these patients are discussed.