This cross-sectional survey study investigates students' perceptions of the effectiveness of Turnitin in detecting plagiarism in academic presentation slides. The data was collected online from 311 students studying at a prominent English-medium instruction university in Turkey. The findings indicated that more than half of them believed in the effectiveness of Turnitin in detecting plagiarism in presentations. Students perceived themselves as academically honest when preparing their presentations. Also, they were aware of the importance of using Turnitin in a required presentation skills course to detect plagiarism. This research can add to the literature since, unlike research on the use of detecting plagiarism in writing, the literature on the use of Turnitin in presentations is not rich and diverse.