Military fighters are at high risk for oral/tooth injuries. Our aim was to evaluate the knowledge and willingness to use preventive measures among this population to reduce oral trauma. A total of 336 fighters were randomly assigned to two groups. The control group answered a structured questionnaire, which included questions regarding: knowledge of the benefits of mouthguard use, past/current use, and willingness to use a mouthguard. The intervention group received a 60-minute dental trauma lecture, and responded to the same questionnaire. Significantly more subjects in the intervention group were familiar with the benefits of mouthguards compared to the control group, but there was no difference between the groups in their willingness to use mouthguards routinely. Discomfort and potential interference to sport performance were the most common reasons for rejection. It seems that a structured lecture is not sufficient for ensuring usage of mouthguards in a military population. Emphasis on motivation or mandating use may be required.