Relationships between developmental disorders and schizophrenia are a current interesting topic of the literature. Several studies have highlighted the presence of motor, social and cognitive developmental abnormalities, or of complex developmental disharmonies in the premorbid history of schizophrenic subjects. The neuro-developmental theory postulates that these abnormalities reflect a subjacent cerebral lesion and are to be considered as precursors of schizophrenia. The model of vulnerability advances, on the other hand, that they are only factors of risk for the disease. Therapeutic positioning depends on the statute of these abnormalities. If the positive impact of early interventions on the course of the disease is nowadays well established, a cautious approach is needed for the open-ended issues of these abnormalities.