Results: Of the 36 patients completing questionnaires 47% (n=17) were males and 52% (n=19) were females. The patients suffered from Lichen planus (n=32, 88%), Pemphigus Vulgaris or Mucous membrane Pemphigoid (n=4, 12%). The involved oral sites were the buccal mucosa (61%), tongue (47%) and gingiva (33%). The study group included 19 patients who reported oral symptoms of VAS higher than 1 (average 2.72). In this group 7 had active ulcerative lesions. Of the study group 78% (n=15) patients changed their diet due to the oral symptoms: 47% (n=9) avoided sour or lemon, 10% (n=2) avoided tomatoes, 47% (n=9) avoided spicy food, and 31% (n=6) avoided alcoholic beverages. Fifty two percent (n=10) avoided either hot solid or salty food. Some avoided few groups of food. None of them reported of weight loss during the year previous to the study. In the control group, 2 patients (11%) avoided spicy food. Conclusion: Patients with vesiculoulcerative oral diseases may change their diet due to oral symptoms. As these diseases are chronic, the long term avoidance of tomatoes and citric fruits (which have preventive effect of cancer) might affect their health, while avoidance from spicy or alcoholic beverages might affect their quality of life.