Background No Indian studies have assessed the implementation of recent policy on pharmacy based surveillance and its contribution in TB notification. So, this study was conducted with objectives to describe: a) pharmacy based TB surveillance and TB notification, and b) experiences of pharmacy based surveillance implementation from the programme managers and pharmacists perspective. Methods A mixed methods study—quantitative (cross-sectional) and qualitative (in-depth interviews) in two selected districts Dharmapuri and Salem districts of Tamil Nadu State, India. Results In 2018, 45 (11%) of 397 pharmacies in Dharmapuri and 90 (6%) of 1457 pharmacies in Salem districts reported sale of anti-TB drugs to 1307 and 1673 persons respectively. Upon validation through direct patient contact 942 (72%) persons in Dharmapuri and 863 (52%) persons were identified as previously ‘un-notified’ TB patients. These patients constituted 20% and 29% of the total TB cases notified in Dharmapuri and Salem respectively. The enablers for implementing this activity were: understanding the importance of notification, availability of resources (manpower, computers) to record, report and validate the patient data, repeated trainings and partnerships. The barriers were: patients' hesitancy to share their details to pharmacists (confidentiality), cumbersome recording and reporting process, difficulties in recording patient details during high workload busy business hours. Conclusion This process contributed about one-fourth of the TB patients notified in these districts. Its implementation needs to be strengthened and should be scaled up in other parts of the country.