Background: Cooperative learning plays a vital role to equip the nursing students with overall needed qualities and skills that suggest clear adoption and effective implementation from clinical nurse educators. Aim: To determine efficacy of instructional program on clinical nurse educators' implementation of cooperative learning at Faculty of Nursing. Subjects and method: A quasi experimental study design was used. Setting: Study was conducted at Faculty of Nursing, Tanta University including all seven academic nursing departments. Subjects: All available (n=80) clinical nurse educators included nursing demonstrators and assistant lecturers enrolled at Faculty of Nursing, Tanta University. Three tools were used; Tool I: Clinical nurse educators' perception regarding cooperative learning implementation Questionnaire. Tool II: Knowledge questionnaire about cooperative learning implementation. Tool III: Cooperative learning implementation observational checklist. Results: Pre-instructional program, majority (83.7%) of clinical nurse educators had low perception level regarding cooperative learning implementation. Majority (88.7%) of clinical nurse educators had poor knowledge level preinstructional program, while post-instructional program high percent (77.5%) of them had good knowledge level and 96.0% of them showed good practice level. Conclusion: Postinstructional program most of clinical nurse educators had good knowledge level with significant improvement compared to pre-instructional program. Also, majority of them showed good practice level regarding implementation of cooperative learning in clinical sessions. Recommendations: Conduct in-service training programs and workshops for qualifying and encouraging clinical nurse educators for using cooperative learning in their clinical sessions