Background: Chronic obstructive pulmonary disease is still defined as a disease state characterized by poorly reversible airflow limitation induced by cigarette smoke and/or other noxious particle and gases. The aim of this study was to assess the compliance toward treatment among adults with chronic obstructive pulmonary disease. Research design: descriptive analytical study was utilized to fulfill the aim of this study. Setting: This study was conducted at outpatient clinic of Menia Chest Hospital, Menia Governorate, Egypt. Sample: A purposeful sample of 115 COPD patients. Interviewing questionnaire was used included six parts. (1 socio-demographic characteristics of COPD patients, (2 medical history of COPD patients (3 assessment of patients' knowledge about COPD, (4) assessment of adults 'compliance to treatment and (5) assessment of adults practices regarding compliance to treatment. Results: 60% of the studied sample had unsatisfactory total knowledge of COPD. Also 64.3% of the studied sample had poor compliance to COPD treatment, 5% of the studied sample had good practices regarding compliance to treatment. Conclusion: Less than two thirds of the studied sample had unsatisfactory total knowledge regarding COPD, less than two of the them had poor compliance to COPD treatment, the majority of them had poor practices regarding compliance to treatment and there were positive correlation between studied sample knowledge regarding COPD and their compliance to treatment. Recommendation: the study recommended that; continuous educational program for COPD patients with chronic obstructive pulmonary disease should be applied periodically in order to improve knowledge, practice and clinical outcomes for those patients.