The phospholipid structure of neuronal membranes is essential for normal functioning of the nervous system. Evidence is accumulating that phospholipid metabolism in both brain and red blood cells may be disturbed in schizophrenia. In particular, in patients with negative symptoms, levels of arachidonic acid and docosahexanoic acid in red blood cell membrane phospholipids are severely abnormal. The membrane hypothesis of schizophrenia may represent a new and fruitful paradigm for future research.