Abstract: Anterior Cruciate ligament (ACL) surgery is one of the most common clinical entities in daily orthopaedic practice. The Aim of the study is to assess nursrs knowledge and practice for patients with ACL surgery. Quasi experimental research design was utilized in this study .This study was conducted in arthroscopy and sports injuries unit at orthopaedic department at Assiut University Hospital. A convenient sample of all available nurses (44 nurses) was included in this study. Data collected by utilizing the designed interview questionnaire sheet consists of biosocial characteristics of nurses , assessment of nurses's knowledge, observation checklist sheet to assess nurses's practice. The results can be concluded that (93.2) of nurses had an poor level of knowledge regarding ACL, all of nurses (100%) had an inadequate level of practice regarding patients who had ACL surgery . It was found that there was a strong relationship (r =.838, P = .0001) between total knowledge and total practice. Conclusion: Nurses`s knowledge and practice regarding patient who had ACL surgery in orthopaedic department of Assiut University Hospitals are unsatisfactory and inadequate. Recommendation :All nurses need to develop nursing care standards for patients with ACL surgery to improve nurses` knowledge and practice