Various reports suggest that adolescents seem to be obsessed with tanning. Existing evidence on attitudes demonstrate that young adults focus on improving appearance through a tan, with protective behaviors often being absent. The popularity of tanning, primarily among the young adult population, further promotes unsafe sun-related behaviors. The aim of this study was to determine the knowledge level of Mostar University students on the harmful effects of ultraviolet radiation (UVR), their attitudes and sun-related behaviors, and whether medical students are more likely to apply preventive measures against UVR in comparison with students from other faculties. The survey included a total of 140 undergraduate Mostar University students: 70 medical students and 70 non-healthcare-related faculty students. The data were collected by completing the personal design questionnaire created for this study. This study shows that Mostar University students have a high level of knowledge about UVR and skin cancer, but their behavior is not sufficiently preventive and appropriate to their knowledge. Medical students often use UV protection measures and employ more preventive behavior than that of other faculty students, but it is still at a low level of prevention. Findings concurred with existing evidence that the knowledge of associated risks from UVR was not sufficient to motivate safer sun-related practices.