Diagnosing schizophrenia in children is difficult, especially in the early stages, and the diagnosis is rarely made. The explanation could be that our knowledge of schizophrenia symptoms in children is insufficient. Moreover, there are no classification systems designed specifically for diagnosing schizophrenia in children. Perhaps diagnosis is rarely made because the disease is a rarity. This article presents a literature review of the present knowledge of early onset of schizophrenia in children and indicates perspectives for future research in schizophrenia.