AIMS : To determine the concurrent validity of St. George Respiratory Questionnaire with Chronic Respiratory Questionnaire as a gold standard measure to measure health related quality of life in respiratory (chronic airflow limitation) diseases . OBJECTIVE: To check the validity of St. George Respiratory Questionnaire in lung cancer population. Methodology: Cross Sectional Study design Results: There is high to moderate correlation between domains of SGRQ and CRQ & there is moderate correlation between domain of SGRQ and SF – 36. Discussion: One way of capturing the personal and social context of patients is to use HRQoL measures. The inclusion of HRQoL in clinical investigations has increased significantly during the last two decades, as has the development of psychometrically sound HRQoL instruments to measure a variety of health conditions. In present study, Results indicate high correlation(r = - 0.826, p<0.05) between SGRQ and CRQ and moderate correlation(r = - 0.697, p<0.05) between SGRQ and SF-36, because SF-36 is generic health related questionnaire while CRQ is disease specific questionnaire.38 Conclusion: Our results suggest that the SGRQ is a valid measure to assess HRQOL in subject with Lung cancer. The SGRQ is valid and compares well with the CRQ and SF-36. There was an excellent concurrent validity for SGRQ and CRQ, moderate concurrent validity of SGRQ with SF-36 in lung cancer.