There is a strong impetus in the psychosis research field to develop interventions that aim to prevent the onset of psychotic disorders. Over the past 15 years there has been a tremendous development in the work aimed at understanding the pre-psychotic period. More recently there has been a focus on developing and testing treatments both pharmacological and psychological that could potentially prevent or delay the onset of psychosis. One of the psychological treatments that has received the most attention is cognitive behavioral therapy (CBT). Relatively few trials have been completed and this paper reviews the existing trials. Implications of these trials for the treatment of this early phase as well as for designing future studies are discussed.