OBJECTIVE: To prospectively describe the clinical characteristics of classical trigeminal neuralgia (TN) in a standardized manner. BACKGROUND: TN is a rare disease and most clinicians only see a few patients. There is a lack of prospective systematic studies of the clinical characteristics of TN. We hypothesized that contrary to current thinking, some TN patients suffer from sensory abnormalities at neurological examination. METHODS: Clinical characteristics such as demographics, pain characteristics, and comorbidities were systematically and prospectively collected from consecutive TN patients in a tertiary referral center in a cross-sectional study. RESULTS: A total of 158 patients were included. Average age of onset was 52.9 years. TN was more prevalent in women (95; 60%) than in men (63; 40%), P = .011, and more often located on the right (89; 56%) than on the left side (64; 41%), P = .043. It affected solely the second and/or third trigeminal branch in 109 (69%) while the first branch alone was affected in only 7 (4%). Notably, 78 (49%) had concomitant persistent pain in addition to paroxysmal stabbing pain. Autonomic symptoms were present in 48 (31%). Patients who had not undergone surgery for TN had sensory abnormalities in 35 (29%). CONCLUSIONS: This, the first study in a series of papers focusing on the clinical, radiological, and etiological aspects of TN, revealed that the symptomatology of TN includes a high percentage of concomitant persistent pain, autonomic symptoms, and sensory abnormalities. These findings offer new insights to the prevailing clinical impression of the clinical characteristics in TN.