The aim of this study was to evaluate both the cortical and the medullary anterior bowing of the femur, and to compare these measurements with current intramedullary nails to assess the adequacy of their design. Methods: Lateral digital radiographic views of left femurs of 104 normal subjects (18-68 years old) were obtained. Radii of cortical and medullary curvatures of femurs were calculated using these images. The values obtained were compared to the radius of curvatures of ten different intramedullary nails. Results: Medullary bowing was between 114 and 1,389 mm (mean: 722 mm, SD: 230 mm) and the cortical bowing was between 109 and 1,666 mm (mean: 770 mm, SD: 267 mm). For males, these values were 114-1,389 mm (mean: 722 mm, SD: 230 mm) and 109-1,666 mm (mean: 770 mm, SD: 267 mm), respectively. For females, they were 114-1,389 mm (mean: 722 mm, SD: 230 mm) and 109-1,666 mm (mean: 770 mm, SD: 267 mm), respectively. The differences between genders were not significant. Cortical and medullar bowing was strongly correlated with age (r=-0.269, p < 0.006 and r=-0.234, p < 0.017, respectively). These significances were produced by females only. Radii of curvatures of intramedullary nails ranged between 150 and 300 cm and were higher than the mean cortical (77 cm) and medullary (72.2 cm) bowings. Conclusion: The difference between the curves of femur and the contemporary femoral nails implicates the inadequacy of the design of such nails for the Caucasian race living in Anatolia. Therefore, such nails should be revised accordingly to prevent the above-mentioned complications.