Background:Pin site infections are a major hazard of external fixation that can be extremely stressful. Nurses are vital in the prevention of pin site infections. Aim:to assess the effect of implementing nursing care guidelines on nurses knowledges and practices regarding external fixation in orthopedic patients. Method:a quasi-experimental research approach was used. Sample:A convenient sample of 40 nurses from the orthopaedic departments of Kafrelsheikh University Hospital and a general hospital was used. Tools:Data were taken using two tools: the first was a self-administered questionnaire sheet, which included two parts: part 1 covered demographic data of the nurses and part 2 included nurses knowledge of the care provided to patients with external fixation. The second tool was an observation checklist for nurses to use before and after external fixation.Results:after implementing the guidelines there were significant statistical increase in nurses knowledge and practice (p0.001), as well as a statistically significant relationship between nurses educational level and their knowledge and practice (p=0.016, 0.001, respectively). Conclusion: The use of the developed nursing care guidelines was efficient in increasing nurses knowledge, preoperative practice, and postoperative practice while caring for patients with external fixation. Recommendations:provide nurses with ongoing training courses.