The aim of this study was to test the reliability and validity of the Tamil version of the Modified Dental Anxiety Scale (MDAS). One hundred and forty-six patients attending the Outpatient Department of SRM Dental College, Chennai, India consented to participate in the study. The assessment tools consisted of a history form, Tamil version of the MDAS questionnaire and a form for Visual Analogue Scale (VAS). The Tamil version of MDAS had a good internal consistency of 0.839. The mean total score decreased with age. Females were more anxious than males (10.16 and 9.43, respectively). Uneducated, unemployed and low income subjects were more anxious than their counterparts who were educated, employed and from a higher income group. Persons who perceived their oral health as poor were more anxious. Independent t-test showed a highly significant difference in the mean total score of the respondents who had postponed their dental visit due to anxiety (t-test 6.494, P < 0.001). VAS and MDAS scores showed a highly significant correlation (r = 0.827, P < 0.001). This supported the convergent validity of MDAS. The Tamil version of MDAS showed acceptable psychometric properties.