We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs and others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized nomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh loci computer. The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal (tare Index are greater by the amount of approximately 8" and 0.5, respectively, (2) the shape of the isthmus cross section is more round , and (3) the distance between the lesser trochanter and the proximal border of the isthmus is shorter by about 15 mm. The results suggested that the femoral component suitable for Asians should be dif- ferent (rom the currently-used components designed and manufactured mostly by European or American companies.