Objective: To determine the knowledge and attitudes of students at the University of Split about mental illnesses considering the type of study, sex and age of the subjects. Subjects and methods: The sample in this study consists out of 280 students from eight components of the University of Split. The used measuring instrument is a newly constructed questionnaire of the knowledge and attitudes of students at the University of Split about mental illnesses. The first part includes 20 statements about attitudes toward psychiatric patients that subjects rate on a five-point Likert scale depending on their personal agreement or disagreement. The second part includes 20 questions in the form of a statement that examine students’ knowledge about mental illnesses, and the possible answers are correct, incorrect, and I don’t know. Other variables used in this study are sex and age of the subjects as well as name, type, level and year of study. Results: The results of the research indicate different attitudes of students towards psychiatric patients. A statistically significant difference in attitudes was found between students of health and non-health studies for 12 out of 20 variables in which students of health studies expressed more positive attitudes towards psychiatric patients. Furthermore, the results of the research indicate a low level of students' knowledge about mental illnesses. The total percentage of correctly resolved answers among the entire sample of subjects is 58.4%. There was a statistically significant difference in knowledge between students of health and non-health sudies for 7 out of 20 variables and a tendency of significant differences for 3 more variables in which students of health studies showed a higher level of knowledge about mental illnesses. However, no statistically significant difference was found in students' knowledge and attitudes considering the sex and age of subjects. Conclusions: Students of health studies have more positive attitudes towards psychiatric patients and have a higher level of knowledge about mental illnesses compared to students of non-health studies. No statistically significant differences in students' knowledge and attitudes considering the sex and age of the subjects were found.