Background:The main cause of mortality in the developed world is coronary artery disease. Low self-efficacy and self-esteem are associated with it. Self-efficacy is a critical, adjustable personal resource that influences rehabilitation adherence and disease outcomes including health-related quality of life in persons with cardiovascular disease. Aim: This study was aimed to determine the effect of social-platform educational instructions on self-efficacy and self-esteem of patients with coronary artery diseases. Subjects and method: Design: A quasi-experimental research design was utilized. Setting: The study was applied in the cardiology unit and outpatients' clinics at Port-Said University Hospital. Subjects: A Purposive sample of (80) adult patients diagnosed with coronary artery disease. Participants were equally and randomly allocated to an intervention and a control group, (40) patients for each one. Tools for data collection: Tool (1) a structured interviewing questionnaire, Tool (2) cardiac self-efficacy scale, Tool (3) cardiac exercise self-efficacy scale, Tool (4) Coopersmith Self-Esteem Inventory, and Tool (5) adult patients' satisfaction with socialplatform educational instructions. Results: The study result portrays that (82.5%) of the study group and (72.5%) of the control group were of the same age from 30-≤ 60 groups with a mean age (45.21 ± 7.02) (46.61 ± 10.43) respectively. The majority of the patients in the study group had satisfactory knowledge levels, and had high cardiac self-efficacy, self-esteem, and practice exercise self-efficacy post-social-platform educational instructions implementation. The mean score of selfefficacy in the intervention group significantly increased across the two measurement time points as well as self-esteem, while it remained significantly unchanged in the control group. Conclusion: Regarding knowledge, cardiac self-efficacy, cardiac exercise self-efficacy post, and after two months of social-platform educational instructions, there was a statistically significant difference between the study and control groups. Social-platform educational instructions were effective and significantly improved adult patients' knowledge, self-efficacy, and self-esteem. Recommendations: We recommend interventions to improve patient's compliance with treatment should be encouraged. Therefore, nurses can use this strategy to improve these patients' selfefficacy and self-esteem.