Measurement of the femorotibial angle was performed in 244 patients (134 women and 110 men) without knee arthrosis with roentgenograms taken in the upright position. The values were grouped according to sex and to decade of life. The average value was approximately 0. As defined by the average upper and lower values of the two types of angulation, the normal value in women was 4 degrees of varus and 4 degrees of valgus. In men, the normal value of the right leg was 5 degrees of varus and 5 degrees of valgus; the left leg demonstrated up to 6 degrees of varus and 5 degrees of valgus. After sixty years of age, 5 percent of patients had angulation above these normal values in valgus and varus.