Emotion profile indeks (EPI) is one of the most used instruments in Croatia for appraisal of personality traits for selection purposes. The instrument is based on forced choice of 62 pairs of posibilities, and the theory contains eight basic emotions/dimension. The interpretation can be made for each dimension separately or for combination of different dimensions. The aim of this study was to determine the existence of differences in the dimensions of EPI questionnaire between different groups of prisoners and the concept of research is divided into three research problems. It examined the differences on the dimensions of EPI questionnaire between male and female prisoners, among returnees and prisoners who are the first time on a prison sentence and between different groups of pepetrators of various crimes (murder, abuse of narcotics, robbery and aggravated theft). Before the researche there was the intention od including perpetrator of rape and sexual exploitation of children, but because of the small number of perpetrators of these crimes, they were compared with each other. Information required for the implementation of this research were obtained with the consent of the Central Office of the Prison System and in collaboration with the Center for diagnosis of Zagreb and it is conducted on a sample od N = 1366 prisoners. The results differ from US standard s in the way that prisoners achieve lower results than the average value of the instrument, but despite that, the differences were determined in various dimensions in all of the investigated problems. The first research problem was to examine differences between male and female prisoners and there were found significant differences. Male prisoners achieve higher results in the dimensions Orientation and Rejecetion, while female prisoners achieve higher results in the demension of Deprivation. The dimension of Agression, Protection, Exploration, Reproduction and Incorporation have no statistically significant differences between these two groups. The second problem of the research was to determine the differences between returnees and prisoners who are the first time in prison. The returnees achieved higher results on dimensions Rejection and Agression, while the prisoners who are the first time in prison achieve higher results on dimensions Reproduciton, Incorporation, Protection and on bias scale. A statistically significant difference between these two groups of prisoners has not been established in the dimensions Orientation, Deprivation and Exploration. As previously stated, the third problem is divided into two parts. In the first part were compared pepetrators of rape and sexual abuse of children due to the small number of inmates who comittet these kind of crime. Comparing these two groups of prisoners we determined that there wes not any statistically significant differences in any dimension of EPI which suggests a certain similarity between these groups. The second part of the third problem was to compare other crimes (murder, abuse of narcotics, robbery and aggravated theft) and a statistically significant difference was found in most dimension, except the dimensions Exploration and Protection. The significance of the results is that to a certain extent can predict the course of serving the prison sentence, the existance of a possible risk of recidivism, but also increase sensitivity to the needs of different groups of prisoners.