We studied 33 cases with distal femur or distal 1/3rd femur fracture treated with closed reduction and internal fixation using retrograde femoral nail for the geometric mismatch analysis of the retrograde nail. Based on a three-dimensional virtual model, we created using computed tomographic pictures a geometric model of the femur with retrograde nail in situ. Six levels were used for the experiment, which were at 130, 150, 170, 190, 210, and 230 mm measured from the condylar surface. Each level was evaluated according to the following criteria: (1) intramedullary canal diameter;(2) percentage of the unreamed intramedullary canal filled by the nail; (3) minimum reamer diameter that required enlarging the canal to accommodate retrograde nail insertion; (4) minimal inner cortical reaming thickness that needed to be removed. (5) The proportion of the cortical bone surface that had to be ground down before the nail could be inserted; (6) The distance between the centre of the intramedullary canal and the nail. The majority of the studied models of the patient had a nail that was significantly mismatched, necessitating substantial reaming of the intramedullary canal to provide room for the nail implantation. A substantial likelihood of clinical problems could result from this. For use in the Indian population, the retrograde nail should be redesigned to be the right size and shape.