This kinematic study investigated the effects of visual factors on the angular oscillations of the head and trunk during various locomotor tasks in 3- to 8-yr.-old children and adults. The oscillations of the head under normal vision were limited and changed little across ages. Oscillations of both head and trunk about the roll axis were the most sensitive to difficulty in maintaining lateral equilibrium. On narrow supports, the lateral oscillations of the trunk increased between the ages of 3 and 6 years, with a maximum amplitude at the latter age and then decreased up to adulthood, suggesting a transition phase around the age of 6 years. Visual restriction had little effect on the control of angular oscillations of the head in children or adults. On a narrow support in darkness, adults increased oscillations of the trunk but reduced oscillations of the head. It can be concluded that, regardless of the age, control of locomotor equilibrium aims at limiting the angular oscillations of the head. Vision seems to contribute little to stabilization of the head.