Background: Nursing demonstrators' clinical teaching competences is the application of knowledge and the interpersonal relationship, decision-making and psychomotor skills expected for the practice role. Six major categories of competency are needed for nursing demonstrator including; professional, interpersonal relationship with students, personal, teaching practice, student evaluation and availability to students competence. Aim of the study was to design, implement, and evaluate an intervention program for nursing demonstrators on clinical teaching competences. Setting: the study was conducted at all nursing departments Faculty of Nursing and nursing students' clinical training areas of Tanta Main University Hospitals.Subjects: All (75) nursing demonstrators who are responsible for students training in clinical areas. Tools of data collection :Two tools were used including actual performance of nursing demonstrators' observational checklist and knowledge about nursing demonstrators' clinical teaching competences questionnaire. Results : preprogram none of nursing demonstrators had good level of total practice score and knowledge about clinical teaching competences. Significant improvement of nursing demonstrators' practice and knowledge was found immediate post and three months post program than preprogram .Conclusion: nursing demonstrators at Tanta University Faculty of Nursing had unsatisfied level of knowledge and performance for clinical teaching competences. Those nurse demonstrators have great need to attend periodically educational program to improve their competency in clinical teaching. Recommendation: conduction pre-employment orientation and periodic educational training program and workshop about clinical teaching competences.