Abstract: The article presents the results of a study of penitentiary personality stress. Penitentiary stress is characterized by negative changes in the emotional state, self-perception, growth of depressive reactions and decrease in adaptive capacity. The relationship between prison isolation and the loss of the ability to meet the actual needs of the individual is examined. The detention and stay in places of detention is a serious stress for the individual, associated with various kinds of deprivations, especially social deprivation. Staying in penitentiary institutions can have a pronounced negative psychophysical impact on the individual, which may be related to the monotony of a prisoner's life, with violation of space-time standards of existence, imbalance of sleep-wake rhythms, and limited access to information. Penitentiary isolation provokes a lot of negative changes in the life of the person: they experience anxiety, fear, feelings of hopelessness, helplessness and constant tension. The purpose of the study is to identify peculiarities of penitentiary stress: significant differences in the emotional state and self-perception of persons with different numbers of convictions held in a temporary detention facility. The subject of the study is the differences in the emotional state and self-perception of persons with different numbers of convictions held in a temporary detention facility. The research methodology includes emotional motivation concept (by V. Viliunas), cognitive theory of psychological stress (by R. Lazarus) and concepts of penitentiary stress (by Ermasov, Chirkov, Debolsky, etc.). The novelty of the research is caused by the fact that the author offers an integral concept of penitentiary stress and choose techniques that allow to reveal the main indicators of psychological stress in isolation as well as combination of mathematical and statistical research criteria. The main findings of the study are the following. The author has revealed significant differences in the emotional state, self-perception of persons with different number of convictions held in a temporary detention center. The persons who first got into the temporary detention center are marked by "oppressed state of health", reduced "activity", mainly "negative mood", experience of helplessness and a high level of depression.