Background: acute bronchial reversibility after inhalation of short acting Beta2 agonists (SABA) has been traditionally used to differentiate asthma from chronic obstructive pulmonary disease. However, it is clear that a positive reversibility test does not exclude the diagnosis of chronic obstructive pulmonary disease. About 24% of patients with COPD met the criteria for reversibility. Aim of the Work: assessment of airflow reversibility & outcomes in patients with COPD. Patients and Methods: this study was conducted at Chest Department, Al-Hussein Hospital, Al-Azhar University and the Chest Hospital in Addakahliah Governorate in the period between January & December 2017. The study included 30 patients with COPD; diagnosed and classified according to [Global initiative for chronic Obstructive Lung Disease (GOLD), 2017]. Results: mean PFT (FEV1, FEV1 / Pred. FVC % and PEFR) showed no statistically difference pre and post BDT. There was highly statistically significant difference in PFTs (FEV1, FEV1 / Pred. FVC % and PEFR) at 4, 6 and 8 weeks compared to Pre BDT. A highly statistically significant improvement in ABG (PaO2, PaCO2 and pH) was found through weeks of study compared to baseline ABG. CAT test results showed highly significant improvement after 8 weeks compared to 0 week. Conclusion: bronchoreversibility is not determined from the first session of nebulizer. Moreover, mostly there is no difference in pulmonary functions mainly forced expiratory volume in the first second between pre and post bronchodilator inhalation. To judge if there is airflow reversibility or not, we must give the patient complete course of treatment for at least one month. Therefore, the lack of acute response to short acting Beta2 agonists does not preclude the beneficial long-term response maintenance bronchodilator treatment.