Postural sway characteristics in a group of 15 left hemiparetic patients were compared with those in a group of 15 right hemiparetic patients using a statokinesimetric platform. The results in the two patient groups were also compared with those derived from a group of 15 age-matched healthy control subjects. Three postural sway parameters were used: the total sway area, the anteroposterior sway and the lateral sway. Hemiparetic patients showed a larger sway area and a lateral displacement of the center of pressure toward the side of the lesion compared to normal subjects. Furthermore, left hemiparetic patients showed greater sway area and lateral displacement compared to right hemiparetic patients. We suggest that the predominance of postural imbalance in left hemiparetic patients could be due to a displacement of postural reference toward the lesion's side.