The stigmatization of the mentally ill includes negative attitudes and behaviors towards persons suffering from a mental illness and is a important problem that occurs daily in our society. The aim of this study was to examine the relationship between personality traits and stigmatization of the mentally ill regarding various socio-demographic characteristics. Students of the University of Zagreb participated in the study in the field of humanities, social and other (natural, technical, biomedical, arts and biotechnical) sciences; 474 of them, both sexes and average age of 23. The IPIP 50 scale (International Personality Item Poolscale, Mlačić & Goldberg, 2007) was used to measure personality, while the Community Attitudes towards the Mentally Ill Scale (Jokić-Begić, Kamenov & Lauri Korajlija, 2005) was used to measure stigma towards people who have a mental illness. The study was conducted online, i.e. a questionnaire was set up and sent to various student e-mail and Facebook groups. The results have show that women, students of humanities and social sciences, as well as people who personally know somebody with a mental illnesses, statistically less stigmatize than men, students of other academic majors and people who do not know somebody who has a mental illness. It has also been established that there is a statistically significant bond between agreeableness and intellect when stigmatizing the mentally ill meaning that while pleasantness and intellect are increasing, the stigmatization of the mentally ill is decreasing. The biggest contribution to the explanation stigmatization of the mentally ill was provided by variables of agreeableness and intellect, as opposed to sex, academic major and personal acquaintance with people who have a mental illness.