The aim of the present study was to compare the kinematics of the foot-ankle complex and knee joints in women with flexible and rigid flatfeet during stance phase of walking. Twenty-nine young women (10 healthy, 10 with flexible flatfeet and 9 with rigid flatfeet) participated in this study. Motion analysis system and a force plate were used to collect research data. The results showed that ankle dorsiflexion was significantly lower in subjects with rigid flatfeet than the other groups. The amount of ankle eversion was significantly higher in subjects with rigid flatfeet than healthy group. Subjects with flexible flatfeet had significantly more knee valgus than other groups. According to the findings, it can be said that subjects with flexible flatfeet were exposed knee injuries as subjects with rigid flatfeet, so it seems necessary to perform treatment in subjects with flexible flatfeet.