Background: Respiratory diseases remain as a cause of frequent visit of emergency department and hospital admission. Inappropriate usage of inhalers and lack of patient counselling leads to uncontrolled state. Proper education and monitoring can manage the disease as well as ADRs. Aim: To study the impact of pharmacist counselling on appropriate usage of inhalers in the treatment of respiratory diseases and their ADR management. Materials and methods: Patients with respiratory diseases, who are using inhalers are recruited in this observational follow-up based study done in a tertiary care hospital in TamilNadu. Baseline data was collected by data acquisition form and case sheet analysis. 4 follow-ups were done in every 1 month interval, after detailed counselling of the subjects. The data were compared with t-test and Z- test. Results: Out of 105 subjects, most of the subjects were counselled by pharmacist(61.9%) than physician (26.66%). The percentage error in inhaler usage was 83.8% in baseline which falls to 27.6% in 4th follow up(p=0.001). In baseline, 85.7% subjects were of score <15 (poorly controlled), but in 4th follow up 83.8% were of sore 19-22(well controlled), which is an impact of appropriate usage of inhalers. Conclusion: This study clearly highlighted that inappropriate usage of inhalers is associated with uncontrolled respiratory diseases and frequent ED visits. The periodic pharmacist counselling leads to controlled disease and ADR management, shows the active role of pharmacist on the topic.