Objective: Little and inconclusive knowledge is known about nurses' perceptions toward electronic health record (EHR) systems and how nurses role performance has been affected after using such systems. This study assessed the relationships between nurses' sociodemographic characteristics, history and pattern of computer technology use, and perceptions toward the EHR system with their perceptions regarding improvement of clinical nursing performance after using the system. Predictors of nurses' perception regarding the effect of the EHR system on improving their clinical nursing performance were delineated. Methods: Descriptive correlational design was used. A standardized self-administered questionnaire was used to collect data from nurses working at a governmental teaching hospital in Muscat, Oman. Nurses were selected randomly from a sampling frame, which consisted of a comprehensive list of employment numbers of nurses at the hospital. Results: With a response rate of 84.5%, 169 nurses returned completed questionnaires. The majority had highly positive perceptions toward the EHR system. A weakly negative correlation was observed between perceiving that EHR system is improving work performance with increasing level of academic nursing education (rho = 0.17, p = .02). Nurses who reported that it was easy to know how to request a test, record etc. using the EHR system [OR: 3.89 (95% CI: 1.54, 9.87), p < .01] were more likely perceive the EHR system as an improver to their clinical nursing performance. While, nurses who had completed at least baccalaureate nursing education [OR: 0.41 (95% CI: 0.19, 0.89), p = .02] were less likely to perceive the EHR system had improved their performance. Conclusions: Nurses should be able to demonstrate basic nursing informatics competencies when dealing with computers and software applications used in healthcare settings. Future qualitative studies are encouraged to explore the lived experiences of nurses, in order to develop better understanding to the impact of the EHR system on nursing practice.