Background The prevalence of skin cancers, including melanoma, has increased significantly in the past five decades. The main environmental factor implicated in their development is excessive sun exposure. Data on sun-protective behaviours in the Turkish population are very limited. Objectives We aim to assess sun protection behaviours and the prevalence of exposure through broad participation among a young adult population in a national university in Turkey. Methods A multiple-choice questionnaire including 27 questions to evaluate sun protection behaviours was sent to e-mail addresses of all undergraduates. From 40 000 undergraduates, 17 769 of them were included in the study, with a response rate of 44.4%. Results Sunscreen usage was the most preferred sun protection method, used by 64% of the study population, followed by the use of sunglasses (60%), tending to remain in the shade (49%), the use of a hat (34%) and wearing long-sleeved clothing (23%). Forty-four percentage of the students used at least two methods, whereas 7% did not use any sun protection method. The prevalence rates of the use of sunscreen, sunglasses, wearing long-sleeved clothing and preferring to remain in the shade in the summer were all significantly higher among women. In addition, the prevalence rates of the use of sunscreen and preferring to remain in the shade were higher among students in the faculty of medicine. Conclusion We found that when compared to the countries with the highest incidences of skin cancer, such as Australia and the United States, young adults in Turkey are protecting themselves more from the sun. This rate was even higher among women and faculty of medicine undergrads.