Background: Patient safety is a major component of healthcare quality, which is defined as the avoidance of causing harm to patients in providing healthcare services. The cardiac catheterization is a procedure that allows a cardiologist to get firsthand information about the patterns of blood pressure and blood flow inside the heart. Aim of the study to assess nurses knowledge and attitude for patient safety in cardiac catheterization unit. A Descriptive research design was adopted to conduct this study. The study was conducted in cardiac catheterization unit at Heart Hospital, Assuit University. Subjects The study included 40 nurses working in mentioned setting. Tools: A structured interview sheet was conducted, structured into three parts included personal data, nurses' knowledge and nurses' attitude for patient safety. Results: It was found that all of nurses (100%) had poor knowledge for patient safety. While (77.5%) of nurses had negative attitude and (22.5%) of them had positive attitude toward patient safety in cardiac catheterization unit. Conclusion: it was concluded that nurses in cardiac catheterization unit had poor knowledge and negative attitude for patient safety. Recommendations: Educational program should be done for nurses in cardiac catheterization about patient safety to improve their knowledge and attitude for patient safety. Keywords: Cardiac Catheterization, Nurses' Knowledge & Nurses' Attitude.