Background: When knee osteoarthritis worsens and conservative measures are ineffective in reducing pain and improving function, total knee arthroplasty becomes the preferred course of action, necessitating a postoperative rehabilitation program. Aim: To investigate effect of physical exercises rehabilitation program on knee function for patients with end-stage osteoarthritis undergoing knee arthroplasty. Design: This study employed a quasi-experimental research design. Settings: The trauma unit, outpatient orthopedic clinic, and orthopedic surgery department of Assiut University Hospital served as the study's locations. Sample: A sixty a (60) patients who were scheduled to underwent knee arthroplasty were included in this study after they were randomly divided into the study and control groups, (30) patients each. Tools: I: Structured Patient Interview Sheet, Tool II: Knowledge assessment sheet, Tool III, Knee Osteoarthritis Western Ontario, and McMaster Arthritis Index (WOMAC). Results: While there was improvement in patient function and knee ability to specific activity for patients undergoing knee arthroplasty during the program phases, the current study found a statistically significant difference in knowledge between the study and control groups following program implementation. Conclusion: Following knee arthroplasty, the patient's knowledge, function, and knee ability to perform particular tasks were significantly enhanced by the application of an exercise program. Recommendations: Applying physical exercise program as mandatory clinical pathway for patient undergoing arthroplasty.