Sequential changes in gait patterns were investigated retrospectively by analyzing the videotape recordings of 20 children with spastic diplegia and periventricular leukomalacia (PVL). The subjects began to walk at 1-5 years of age, and their walking was examined to 6-16 years of age. Many of the ambulatory children with spastic diplegia walked with flexed hips, knees and ankles. At the final walking examination, the knee was flexed during the stance phase in both legs and in all cases. In addition, the ankle was over-plantarflexed during the stance phase in nine cases or 14 legs, and dorsiflexed in 15 cases or 26 legs. At the initial walking, the knee was over-extended during the stance phase in seven cases or 12 legs, and was flexed in 15 cases or 28 legs. Also, the ankle was over-plantarflexed during the stance phase in 14 cases or 22 legs, and dorsiflexed in ten cases or 18 legs. Bilateral excessive ankle plantarflexion or a recurvatum knee was observed in a portion of the children at the initial phase of walking only. In the diplegic children with PVL, the gait pattern was variable.