Background: Many clinical and paraclinical studies related to coronary artery disease have been done in Vietnam in recent years. However, there have been no studies on nurses’ knowledge and practice regarding patient care after coronary angiography (CAG) or percutaneous coronary intervention (PCI). This study was conducted to assess nurses' knowledge and practice on patient’s safety after CAG or PCI and its associated factors. Methods: A descriptive cross-sectional study was conducted from December 2019 to June 2020 at the Department of Internal Cardiology, Interventional Cardiology, Intravascular Intervention, and Intensive care unit/Coronary care unit in three general and specialist hospitals in Ho Chi Minh city, Vietnam. 167 nurses who have taken care of patients after CAG or PCI were included in the study through using convenient sampling technique. A translated self-administered questionnaire was utilised. This self-reported survey achieved 100% response rate. Statistical analysis was performed by the Chi-square test (X2). Statistical significance level was at p<0.05 to determine factors related to nurses’ knowledge and practice. Prevalence ratio (PR) with 95% confidence interval (95% CI) were also used to measure the association. Results: The study findings revealed that only 36% of the study sample had a good knowledge while 78% of them had a good practice on patient’s safety after CAG or PCI. There were association between educational level, working place with the knowledge (PR=1.87-1.92, p<0.01) and practice (PR=1.18-1.35, p<0.05) on patient’s safety after CAG or PCI among Vietnamese nurses. Besides those factors, the number of years working in cardiac specialty were also found to have an association with the practice. A moderately positive correlation between the knowledge and the practice towards patient‘s safety after CAG or PCI has been identified in this study (PR=1.27, 95% CI [1.09 – 1.47], p=0.005). Conclusions: More than a half of the study sample had poor knowledge but performed good practice in some items of care for patients after CAG or PCI. There was positive association between the knowledge and practice about patient’s safety after CAG or PCI among Vietnamese registered nurses. Educational training programs for staffs working in coronary angiography or percutaneous coronary intervention is recommended to develop.