The objective of this study was to assess the reliability of the Balance Scale. Subjects were chosen from a larger group of 113 elderly residents and 70 stroke patients participating in a psychometric study. Elderly residents were examined at baseline, and at 3, 6 and 9 months, and the stroke patients were evaluated at 2, 4, 6 and 12 weeks post onset. The Cronbach's alphas at each evaluation were greater than 0.83 and 0.97 for the elderly residents and stroke patients respectively, showing strong internal consistency. To assess inter-rater reliability, therapists treating 35 stroke patients were asked to administer the Balance Scale within 24 hours of the independent evaluator. Similarly, caregivers at the Residence were asked to test the elderly residents within one week of the independent evaluator. To assess intra-rater reliability, 18 residents and 6 stroke patients were assessed one week apart by the same rater. The agreement between raters was excellent (ICC = 0.98) as was the consistency within the same rater at two points in time (ICC = 0.97). The results support the use of the Balance Scale in these groups.