Abstract: The subject of this research is a personal myth of the sentenced for extremism. The goal consists in examination of the inner world of convicts through their personal myth as a potential of psychocorrection work. The conceptual ground for this research is the theory of multidimensional lifeworld structure, whole the methodological approach is the construction of a personal myth. The authors elucidate the experience of using the possibility of construction of a personal myth in existential psychocorrection work with those convicted of extremism. The fundamental principles of counseling work with inmates in a penitentiary facility are reviewed. The study involved male extremist offenders serving sentence in the Federal Penal Enforcement Service of Tomsk. The dynamics of the process of existential psychocorrection consisted in the development of self-awareness, modifying the perceptive structures and transforming the concept of “Self and the outside world”. In the context of existential psychocorrection, personal myth is not a psychotechnology or an approach used for solving the problems of personal existential problematic, but a qualitative method determining the approaches towards solution of such problems.