Background: Chronic obstructive pulmonary disease (COPD) is one of the main causes of morbidity and mortality worldwide and is expected to become the third cause of death and the fifth cause of disability-adjusted life years in 2020. Aim of the study: The study aimed to evaluate the effect of health educational guidelines on knowledge, self-management practice and self-efficacy of patients with COPD. Subjects and methods: Research design: A quasi experimental one group pre/posttest design was utilized to achieve the aim of the study. Study Setting: The study was conducted in out patients Clinic at Zagazig University Hospital. Sample: A purposive sample included 30 patients with COPD were recruited in this study. The program implemented through 10 months from November 2017 to August 2018. Tools of data collection: Three tools of data collection were used: 1- A structured interview questionnaire. 2- Self efficacy scale.3-Observational checklists. Results: There was a significant improvement of knowledge score post intervention with Mean ± SD 22.6000 ±2.48582. Also, there was a significant improvement of patients' practice in using incentive spirometry, pursed lip breathing, diaphragmatic breathing, deep breathing and coughing exercise, and using inhaler after intervention than before with statistical significance difference P= 0.00. There was a statistical significant improvement of patients' self efficacy after intervention. In addition to, there was a strong positive correlation between patient's knowledge, practice and self efficacy. Conclusion: it can be concluded that nursing intervention guidelines has statistically significant positive effect on patients' level of knowledge and practices that reflecting on significant improvement of their self efficacy. Recommendation: it is recommended that conducting comprehensive health education programs for patients with COPD in outpatients' clinics with simplified printed guidelines through leaflets, brochures or booklets taught to the patients by skilled personnel. Key word: Chronic Obstructive Pulmonary Disease (COPD), Self- Efficacy.