There is no doubt that every member of the society would agree that all health care providers should be competent in practice. Nursing is a profession requires intellectual and technical skills to provide quality patient care. For nurses to work efficiently and effectively the areas of competency must be identified for specific roles and setting. Clinical teaching is vital for the preparation of professional nurses who can function competently and independently in a diversity of nursing situations Aim: this study was aimed to evaluate the proposed competency based performance as an indicator for assessing clinical competency of nursing students as well as to determine the opinionnaire of nursing students and instructors about the assessment system Subjects and Methods: The study was conducted at the Faculty of Nursing and at Assiut University Hospitals. The study sample consisted of all nurse students who were enrolled in the fourth academic year (171) as well as 12 clinical instructors: Three tools were used for collection of data: two for students, and one for clinical instructors. I-Assessment System Tool (Dolan (2003). It includes six competency indicators namely care delivery, communication, safety, organization and management, teaching, and professional judgment. Validity and Reliability of the tool were 0.85- 0.93. The second and third tools were respectively students and clinical instructor's opinionnaires. Results: there were statistically significant improvements in all almost domains at both the post and retention phase, and there were statistically significant improvement as regard the total competencybased achievements of students at the post and retention phases have statistically significantly improved. Conclusion and Recommendations plans are urgently needed for instructors' workshops about competency assessment, the Faculty must consider the need for more staff members in its plan for the future, to help in evaluation of students and to prepare a competent nursing student, and further researches are needed to evaluate the outcomes of competencies not only in terms of individual nurses student, but also in terms of patient and unit outcomes.