Schizophrenia is a complex disease. A more complete understanding of its neurobiology has been hampered by the fact that most data have been based on studies of patients diagnosed according to either the ICD-10 or the DSM-IV, i.e. patients suffering from pathogenetically different diseases. In recent years, some research projects have attempted to take this into account by focusing on biologically more valid endophenotypes. The current brief review summarises central functional, neurochemical, and structural endophenotypes - and where possible also link these endophenotypes to each other.