Preventive endeavours in psychotic disorders have been hampered by many obstacles over the past century. One important barrier has been the corrosive pessimism which has attached to the treatment prospects for schizophrenia in particular since the time of Kraepelin, and the isolation of this disorder from progressive models of preventive intervention which operate in general health care. This paper outlines a rationale, logic and model for realistic preventive efforts in early psychosis, focusing on indicated prevention in the pre-psychotic phase and early intervention from the onset of frank psychotic symptoms through the early years of illness. The latter is discussed through a series of clinical challenges which will be familiar to clinicians during this phase of illness. The existing evidence is introduced and the gaps indicated. It is argued that the case for a preventive approach possesses more than face validity alone, and that momentum is building for a significant paradigm shift. If this to be securely based and durable, it will need to become increasingly evidence based and demonstrate cost-effectiveness. The nature of the evidence and the strategy for its assembly are also considered.