The pathogenesis of oral lichen planus (OLP) remains to be fully elucidated; however, certain psychoneurological factors may influence the onset and exacerbation of OLP. The aim of the present study is to evaluate the intensity of negative emotions in patients with OLP. A cross-sectional, questionnairebased study was performed. The sample consisted of 52 subjects, comprising 26 patients with OLP (OLP group) and 26 controls (CTRL group). The Depression Anxiety Stress Scale 21 (DASS-21) was used for psychometric evaluation. The patients were also asked about their attitude toward the disease, treatment, and interference of the disease on daily life. The mean level of depression was 12.54 ± 6.6 in the OLP group and 7.69 ± 5.22 in the CTRL group (P = 0.006). The mean level of anxiety was 11.15 ± 7.95 in the OLP group and 6.62 ± 4.86 in the CTRL group (P = 0.018). The mean stress levels were 8.69 ± 7.06 and 3.85 ± 3.18 in the OLP and CTRL groups, respectively (P = 0.003). Severe and very severe scores of depression and very severe scores of anxiety and stress were present in the OLP group, whereas these emotions were normal in the majority of controls. Depression, stress, and anxiety may be involved in the pathogenesis and course of OLP.