Immobility refers to a reduction in the amount and control of movement. Immobility can adversely affect all physiological bodily systems. The nurseʹ interventional actions for immobilized patient should support the normal functions of the body and maintaining the strength and flexibility of the musculoskeletal system. Aim of this study was: To assess the effect of implementing guidelines for nurses caring for immobilized orthopedic patients on their performance. One research hypothesis: Was formulated that Nurses' performance related to caring for immobilized orthopedic patients will be improve after application of developing guidelines. Design: A quasi-experimental design was used. Setting: This study was conducted in the orthopedic department at Benha University Hospital. Subject: (convenience sample).consist of all available nurses (n=05) working at orthopedic departmentTools: Two tools were used, I a nurses' assessment sheet to assess nurse knowledge & II Observational check list for assess nurses' practice regarding caring for immobilized orthopedic patients Results: This study showed that the majority of the nurses had unsatisfactory knowledge and practice regarding caring of immobilized orthopedic patients pre guidelines implementation (888 and 068) which improved significally immediately post guidelines implementation (828 and %6.58). Conclusion The majority of the studied nurses had unsatisfactory level of performance (knowledge and practice) regarding caring of immobilized orthopedic patients pre guidelines implementation. Meanwhile, the majority of the studied nurses had statistically significant improvement in their performance post guidelines implementation, which supported the study hypothesis. The study Recommended That an educational program and continuous in-service training programs should be prepared to help the nurses to revise, acquire and develop their knowledge and practice regarding caring of immobilized patients.