The effectiveness of Reality Orientation (RO) as treatment for disorientation and behavioral deficits in institutionalized elderly adults was assessed over a one-year period, with evaluations at 6-month intervals. Residents of a home for the aged with varying degrees of disorientation and disability were treated with a 24-hour RO program and were compared with a control group. A subsample of disoriented residents also attended RO classes and was compared with controls. Treatment effects were assessed with a Mental Status Questionnaire (MSQ) and ratings of Activities of Daily Living (ADL) and interpersonal behaviors. Compared with controls, who showed deterioration, the subsample attending RO classes showed slight, statistically significant improvement on the MSQ after 6 months. There was no favorable effect on ADL or other measures. Comparisons with other studies suggest that advanced age, severity of disorientation and disability limit the effectiveness of RO.