The study was conducted among patients diagnosed as pulmonary or extra pulmonary tuberculosis attending DOTS facilities at New Delhi Tuberculosis Centre, Delhi. The objectives of the study are; to evaluate the impairment of health related quality of life in patients of tuberculosis by evolving a HRQL questionnaire (DR-12 score) and to validate the new scoring method by making serial assessments of health related quality of life of the patients during anti-tubercular therapy initially, at the end of intensive phase (IP) and at the completion of treatment. Seventy eight consecutive patients aged between 15-60 years put on DOTS treatment at New Delhi Tuberculosis Centre, Delhi were subjected to a HRQL questionnaire (DR-12 score) at 0 week, 8 weeks and at the completion of treatment. The new scoring method contained questions on twelve parameters related to symptoms, physiological, psychological and social well-being of TB patients. The patients were asked to evaluate these twelve parameters on a score of 1-3. All the individual parameters were equally weighted. The data so obtained regarding these scores was analysed using unpaired t-test, paired t-test, one way Anova test and Pearson corelation coefficient test. The patients who converted at the end of intensive phase had a significantly higher gain in scores as against, those who failed to convert even after extension of intensive phase (p=0.019). Significantly higher scores were observed among those who had a favourable outcome as against those who had unfavourable outcome at the completion of treatment (p=0.029). Thus, DR-12 score was found to have a strong construct validity and useful additional evaluative tool for patients under DOTS therapy.