Background: During nineteenth century, the advice of Sir Astley Cooper (1892) with regard to high femoral neck fractures was to treat the patients and let the fracture go. He recognized that most patients who sustained this injury tolerated prolong immobilization very poorly. Any treatment which requires prolong immobilization will care for the hazards like cardio-pulmonary problems, thrombo-embolie phenomena, urinary tract problems and decubitus ulcer in the elderly patients. Objective: To evaluate the effectiveness of replacement hemiarthroplasty by Austin-Moore prosthesis with autogenous cancellous bone graft in treatment of fracture neck of femur. Materials and Methods: This is a prospective observational study carried out at Dhaka Medical College, Orthopaedic Surgery Department from June 2006 to December 2007. Data were collected in preformed data collection sheet which included history, physical examination, radiographic findings, preoperative monitoring, and post-operative follow-up. Functional outcome was assessed by Harris hip scoring system. Total score of ten clinical parameters- pain, limp, need of support for walking, walking distance, stair climbing, put on shoes, sitting in chairs, deformity, range of motion & use of public transport finally evaluated to measure functional outcome. Evaluation of outcome assessed by Harris Hip score (HHS). Then statistical analysis was done to see comparative evaluation outcome at week 6 and at month 12 by computer based program SPSS, version 11.5. Results: A total of 21 cases of fracture neck femur were treated by replacement hemiarthroplasty with Austin Moore prosthesis. Autogenous cancellousbone graft harvested from resected femoral head of affected side was applied to fenestrations in the Austin Moore prosthesis in each case. Four of the twenty one patients were lost to follow-up. Of the remaining 17 patients functional outcome is evaluated. Age distribution was ranging from 65 to 85. Mean age (71.88 ±354) Sex dist