Background: Clinical teaching is the core of nursing education and essential component for development of professional nurses. Clinical instructors are the clinical faculty members that facilitate the learning and competence of small groups of nursing students in professional practice environments. Aim of the study: to conduct an intervention program for clinical instructors about clinical teaching. Subjects and Methods: Research design: A quasi-experimental intervention design. Setting: Faculty of Nursing-Fayoum University. Subjects: included 40 clinical instructors working at Faculty of Nursing-Fayoum University, who agreed to participate in the program and had one year experience to have experience regarding clinical teaching. Tools of data collection: Three tools were used for data collection: Clinical teaching knowledge questionnaire sheet, Clinical teaching performance checklist, and effectiveness of clinical teaching self-behavior tool. Results: clinical instructors had poor clinical teaching knowledge and unsatisfactory level of clinical teaching performance and self-behavior in preprogram. Post program there were increases to good clinical teaching knowledge and to the satisfactory level of clinical teaching performance and self-behavior. Additionally, there was a positive correlation between clinical teaching knowledge, performance, and self-behavior of clinical instructors throughout the program phases. Conclusion: there are significant differences in clinical instructors' knowledge, performance, and self-behavior before and after implementation of clinical teaching program. That means clinical instructors' knowledge increases from poor level in preprogram to good level immediately post and three months later after program intervention. As well clinical instructors 'performance and self-behavior increases from unsatisfactory level in preprogram to satisfactory level immediately post and three months later after program intervention. Recommendation: set up an orientation and continuing education sessions for clinical instructors regarding requirements for effective preparation of clinical instructor's roles to develop their clinical teaching knowledge. Regular meetings between mentor and clinical instructors to give them feedback to improve their knowledge, performance, and self-behavior, focusing on their tasks and specific needs to put them on the right track