Abstract Background: Nurses performance remains long standing determinates of quality care rendered for patients, many factors affecting nurses' performance include physical, psychological, professional, patient related factors and work related factors. Sudden cardiac death is one of the most common reasons of death worldwide which prevented by inserting a pacemaker. Study’s purpose: To evaluate factors affecting nurses' performance regarding care for patients with permanent pacemaker Subjects and Methods: Research design: A descriptive design was utilized. Setting: The study was conducted in all cardiac intensive care units at Zagazig University Hospitals Subjects: A convenience sample of all available nurses (60). Tools of data collection: Two tools were used to collect the study data: Self-administered questionnaire about demographic characteristics of the studied nurses, nurses' knowledge and factor affecting nurses' performance. Observational checklist to assess level of nurses practices. Results: Four fifths (80.0%) of studied nurses had unsatisfactory level of total knowledge, the most (90%) of studied nurses had unsatisfactory level of total practice and (91.7%),(63.3%), (91.7%) of factors related to nurse, factors related to patient, factors related to work respectively affected nurses' performance regarding care for patients with permanent pacemaker Conclusion: Most of studied nurse had unsatisfactory performance regarding care for patients with permanent pacemaker and the most of studied nurses their performance affected by nurse, patient and work related factors. Recommendation: Training programs are recommended to improve nurses performance regarding care for patients with permanent pacemaker. Keywords: Nurses' Performance, Factors, Permanent Pacemaker