For decades, autobiographical narratives have formed an integral part of school prevention and educational work in Germany. They are not only widespread in the prevention of extremism but are also used to impart historical thinking or to prevent violence and substance abuse. For the most part, however, sound evaluations on this topic are not available. This monograph provides the first comprehensive academic examination of school-based prevention measures conducted by former extremists: On the one hand examining the application practice across Germany by means of a data collection consisting of interviews, postal survey and media analysis; On the other hand comprehensively evaluating, with robust design and sufficiently large sample, an illustrative primary prevention school measure conducted by a former right-wing extremist. The focus lies on the effects of the measure on the pupils.