Increasing evidence from clinical as well as from epidemiological and basic research shows that oestrogens exert protective effects in schizophrenia. A brief overview of these protective effects will be provided, and potential therapeutic implications will be discussed. If these effects are confirmed, they could have important implications for prophylaxis and treatment. For instance, consideration would need to be given to oestrogen replacement in peri- and postmenopausal women with schizophrenia, adjunct oestrogen therapy in women with oestrogen deficiency syndromes, cycle-modulated neuroleptic therapy in women with frequent perimenstrual relapses, and/or emphasis on prolactin-sparing atypical neuroleptics in women with hypoestrogenism. Further research is urgently needed since there may be direct therapeutic benefits for women.