The objectives of this study were (a) to explore the effectiveness of sensory stimulation therapy under controlled conditions, and (b) to ascertain the short-term effectiveness after treatment ceased. Thirty geropsychiatric patients were divided into three treatment condition groups: sensory stimulation, staff attention, and standard hospital treatment. Twenty-seven subjects completed the 12 weeks of treatment and 6 weeks of follow-up. Assessments were made prior to treatment, upon completion of treatment, and six weeks after treatment was completed. The results showed that those subjects who completed the sensory stimulation treatment significantly improved and maintained their improvement in the areas of personal hygiene and interest in group activities relative to the subjects in the other two treatment approaches studied. Discussion focuses on the implications of sensory stimulation for the treatment of elderly psychiatric patients.