Aims: To test the validity of the use of the Douleur Neuropathique en 4 Questions (DN4) questionnaire for burning mouth sydrome (BMS) patients, and to differentiate patients by measuring the time course of the pain in BMS patients over a period of 7 days with a visual analog scale (VAS). Methods: Patients completed the DN4 questionnaire and a VAS every hour for 7 days. The data were expressed as mean ± SEM. Correlations were searched using the Spearman correlation test with a significance level at P .05. Results: Data were fully analyzed for the 22 patients (21 females, 1 male, mean [± SEM] age 62.7 ± 2.3 years) for the DN4 and 17 patients for the VAS. DN4 scores ranged from 2 to 7 (mean score: 3.9 ± 0.3), and 59% of the patients had a DN4 score >= 4. Burning was found in all the patients, followed by pricking pain (pins and needles) and allodynia (pain on brushing) (both 68%), tingling (45%), numbness (32%), itching (27%), and electrical discharges (23%). Monitoring the hourly time-course of the pain led to the identification of two groups with intermittent or constant pain. In the latter, averaging the VAS for 7 days enabled plotting a curve, the slope of which could be calculated. The range of the slopes was 0.00 to 0.59, and a regular increase of pain during the day was seen for the majority of the patients. Conclusion: The findings support the use of DN4 as a tool for screening BMS and reinforce the view that BMS is a clinical manifestation of a neuropathic disease. The methodology of this study can be used for a better description of the patients and the identification of subgroups. Keywords: burning mouth syndrome, DN4, pain, visual analog scale