The proximal and distal parts of the femur show the differences between the sexes. Head diameter and the breadth of the epicondyle of the femur are known to distinguish males from females. The proximal end of the femur is studied to determine sex using discriminant analysis but; its distal end is not done. This study aims to develop an equation specific to Koreans by using the medial and lateral condyles of the femur, and to demonstrate the usefulness of equations for specific population groups. We used three-dimensional images from 202 Korean femurs. Twelve variables were measured with a computer program after the femurs were in alignment. Eleven variables showed a statistically significant difference between the sexes (P<0.01). The most accurate equation used width of the medial and lateral condyles (WDC), with of the medial condyle (WMC), depth of the lateral condyle (DLC), and depth of the intercondylar notch (DIN) (94.1%), and is as follows: The second highest accuracy was 90.1% for the width dimensional group and WDC. This study shows that the medial and lateral condyles of the femur should be helpful for sex determination in situations where the skull and pelvis are missing and part of the femur is available. The study also demonstrates the need for different equations for different population groups.