Background: Fractures of the femur are among the most common fractures encountered in orthopaedic practice since this long bone along with tibia form the principle load bearing bone in the lower extremity.They also form the strongest bones of the body, however, they are frequently fractured due to multiple causes. With recent advances in biplanar imaging, there has been a renewed interest in closed intramedullary interlocking nailing. Hence an attempt has been made to study the role of intramedullary interlocking nail in fracture femur among adults. Aims and Objectives: To study the role of intramedullary interlocking nail in fracture femur among adults in a tertiary care hospital, Andhra Pradesh, India. Material and Methods: Study Design: Prospective study Study Area: Tertiary care hospital, Rajahmundry. Study Period: 18 months (July 2011 to Dec 2012) Study Tools: A Predesigned and Pretested questionnaire, Measuring tape, Stethoscope, X-ray Chest and Femur, Routine blood investigations, Urine routine, ECG Sample Size:102, Statistical Analysis: Analyzed using Microsoft Excel 2007 and Epi info version 3.5.2 Results: The age of presentation varied from 19-64 years with a Mean age of 37.39.The incidence was significantly higher in Males (42 males and 8 females), Right side (65.2%) involvement was more, RTA was the main cause of trauma. 84 (91.28%), Closed type 72 (78.24%) of injuries was more commonMajority of the cases were Oblique type 48 (52.16%).Most of the fractures occurred at middle third zone 36 (39.12%).Most common complication was Hip Pain, 16 (17.39%).Union was achieved in majority 76 (82.6%) of the cases, between 12-24 weeks.Mean union time was 16.6 weeks. Conclusions: Closed interlocking nail fixation is the procedure of choicefor femoral shaft fractures.