Chronic obstructive lung diseases like Asthma and COPD are accompanied by diversity of symptoms, demand and increase in health care utilization, medication cost and loss of productivity to the individual. The major treatment option is by inhalation therapy, as it can deliver drugs into airways, achieving greater local concentration with a very minimum risk of side effects. The aim of our study was to analyze the impact of clinical pharmacist initiated patient counseling in Asthma and COPD patients. The major objectives were to evaluate the patient knowledge on the proper use of inhalers, to assess the knowledge of patient regarding disease condition and to study the impact of clinical pharmacist initiated patient counseling on medication adherence. The study was carried out in Pulmonology department in a tertiary care teaching hospital. It was a prospective interventional study using retrospective data as control and the patients visiting Pulmonology department and prescribed with inhalation therapy with age ≥18yrs were selected. We identified problems with proper use of inhalation techniques in the prospective arm and also provided proper education to improve knowledge and adherence of patients and compared with the retrospective arm. There was statistically significant improvement in knowledge score and medication adherence of patients in the intervention group as compared to control group. The study proves that intervention of clinical pharmacist can bring about major changes in the knowledge about the disease and inhalation techniques, adherence related attitude of the patients eventually affect the better health of the patients.