A powerful motivation for clinicians working in the fuield of trauma is the wish to prevent or minimize chronic posttraumatic reactions by early interventions. This paper illustrates the process and the elements of important programs that have been introduced into the psychological or psychiatric literature. Studies that have been done to evaluate these programs are discussed. With regard to early interventions given to traumatized victims regardless of whether they suffer from posttraumatic stress or not, it is clearly shown that the evidence that these programs havwe a substantial positive benefitis is disappointingly scarce. However, with regard to the treatment of acute stress disorder, a brief cognitive-behavioral program appears to effectively prevent the development of chronic posttraumatic stress disorders. In summary, it has to be noted that much more on this issue is needed.