Background:Epidemiologic researches about oral mucosal lesions have been performed in different populations. But, in dermatology outpatients, oral mucosal lesions have not been investigated previously.Objective:We aimed to determine the prevalence of oral mucosal lesions among dermatology outpatients and the relationship between OML and smoking, alcohol intake, denture and dental filling use and skin diseases.Methods:Randomly selected 1041 dermatology outpatients were examined for dermatological diseases and oral mucosal lesions. All of the patients were questioned about smoking, alcohol intake, denture and dental filling use.Results:In 235 patients, oral mucosal lesions were recorded. 268 (25.7%) of the patients had history of smoking, 42 (4%) drinking alcohol and 180 (17.3%) denture and dental filling. 32 (64%) of the smokers, 54 (30%) of denture users and 10 (23.8%) alcohol consumers had at least one OML. Age and smoking were found as significant risk factors for oral mucosal lesions. Fissured tongue was the most common oral lesion and it was seen significantly higher in patients with denture. Smoking was risk factor for coated tongue and linea alba .Conclusions:Oral mucosa should be examined carefully even if the patients do not attend with the complaint of oral lesions, especially in elderly patients, smokers and denture users.