BACKGROUNDTuberculosis has been a major case of suffering and death since time immemorial. Thought to be one of the oldest human diseases, the history of Tuberculosis is at least as old as mankind. The aim of this study is to identify the relationship between erythrocyte sedimentation rate and time to sputum smear conversion in active pulmonary/laryngeal tuberculosis. The study on Relationship between ESR and time to sputum smear conversion in active pulmonary tuberculosis/laryngeal tuberculosis was conducted among 50 patients who attended as outpatients at Meenakshi Hospital, Avadi, Chennai -600055.