OBJECTIVE : To validate the use of Chronic Oral Mucosal Diseases Questionnaire in oral submucous fibrosis. METHODS : Hundred consecutive oral submucous fibrosis (OSF) patients were requested to respond to Visual Analogue Scale (VAS) score and complete the Oral Health Impact Profile 14 (OHIP 14) and COMDQ. Spearman's rho correlation was used to assess the relationship between VAS and COMDQ score and COMDQ and OHIP 14 score. The reliability of the instrument was assessed using Cronbach's alpha analysis. Discriminant analysis was used to assess if COMDQ significantly differentiated between OSF population with and without any prior treatment done as well as OSF with mouth opening less than and more than or equal to 25 mm. RESULTS : The Spearman's correlation coefficient showed a high significance between the different domains of COMDQ and OHIP 14 and COMDQ and VAS. This study demonstrated a good convergent validity between the overall COMDQ and OHIP 14 scores (0.88).The overall Cronbach's alpha value was found to be 0.75 indicating an acceptable internal consistency reliability of COMDQ. The tool was unable to differentiate between patients with mouth opening between less than and more than or equal to 25 mm and patients with and without prior treatment. CONCLUSIONS : These results provide evidence that COMDQ can be used for OSF patients. CONCLUSIONS : COMDQ could be used as a valid and reliable tool for further clinical OSF research.