The Functional Standing Balance (FSB) Scale was designed to obtain measurements of standing balance and to identify the problems typically faced by people with stroke. The purpose of this study was to investigate the validity of measurements obtained with the FSB Scale for use in the acute and chronic phases of stroke by comparing the measurements obtained with the FSB Scale with those obtained for postural sway and lateral symmetry by use of a force platform. Measurements were obtained for 26 people with recent strokes (ie, strokes within 3 weeks of data collection) and for 28 people with long-standing strokes (ie, strokes of 6 months' duration or older). The FSB Scale consists of 3 components: weight distribution, balance without movement, and balance with movement. Measurements of balance performance were compared with measurements of anteroposterior and lateral sway velocity obtained on a force platform. The weight distribution on 2 digital scales was compared with the lateral symmetry measured on the force platform. The highest correlations were found between the FSB Scale balance measurements and the measurements of anteroposterior sway velocity obtained on the force platform with feet apart and eyes open. The correlations (r) were -.68 and -.67 for the group with recent strokes and -.74 and -.91 for the group with long-standing strokes. The correlations (r) between weight distribution measured on the digital scales and lateral symmetry measured on the force platform were.44 for the group with recent strokes and.52 for the group with long-standing strokes. The subjects whose results on the FSB Scale were poor had higher sway velocities on the force platform than the subjects whose results on the FSB Scale were good. The results of this study suggest that the FSB Scale provides the same kind of information as that obtained for sway velocity and lateral symmetry as measured with the use of force platforms in both patients with recent strokes and patients with long-standing strokes.