Leisure time has existed since the existence of man and civilization, and in the simplest terms it represents the time in which an individual indulges in activities of his own choice. On the other hand, mental health is an important part of the overall health of every individual, and is defined as a state in which a person can realize his potential, deal with everyday life stresses and be able to productively work and contribute to his community. Not so many informations can be found in professional literature about the relationship between leisure time and mental health. If certain research is carried out on the mentioned topic, most of them examine the connection between engaging in physical activities and mental health. Therefore, the main goal of this research was to examine the impact of leisure time on the mental health of university students of the Republic of Croatia and Italy. In total, 139 male and female students participated in the research, and it was determined that Croatians more than Italians, and male students more than female students, dedicate their leisure time to sports activities and hobbies. In addition, the mutual connection between leisure time and mental health has been established, in the sense that better spent leisure time results in better mental health.