Introduction: Neck of femur fractures are common injuries in the trauma center. In developing countries, there is high incidence maltreated femoral neck fractures due to lack of treatment facility. Non–union and AVN of fracture in the neck of femur increases day by day. In case of more than 6 months old fractures regardless of age or stage, prosthetic replacement (hemi or total) is the treatment of choice. Method: It was a descriptive observational type of study carried out in National Institute of Traumatology and Orthopaedic Rehabilitation (NITOR) and private hospitals of Dhaka from August 2015 to June 2017. Total 18 samples were included in this study to evaluate the functional outcomes of modular bipolar femoral prosthesis in the treatment of neglected femoral neck fractures Results: The pain status of patients decrease significantly following operation. In almost all cases pain was decreased significantly (P value <0.05). According to Harris hip score results were 44.44% excellent, 33.33% good, 16.67% fair and 5.56% poor. Conclusion: Satisfactory functional results, minimal incidence of major radiological complications and the biomechanical advantage make modular bipolar prosthesis a dependable endoprosthesis in neglected fracture neck of femur.