Objective: To investigate the effects of a systematic intervention with a case manager concept and rehabilitation periods compared to standard aftercare in elderly community-dwelling patients discharged from the hospital after a delirium episode. Design: Before/after intervention cohort study with 3-year follow-up. Settings: Acute geriatric wards of a city hospital and a private rehabilitation center. Subjects and Methods: The intervention group consisted of 51 community-dwelling people over 65 years of age without severe underlying disorders, who were consequently admitted as emergency cases to the hospital because of a delirious state or who were delirious immediately after admission. The intervention included continuous support and counseling by a nurse specialist and rehabilitation periods at a rehabilitation center. The control group consisted of 51 age- and gender-matched patients admitted to the same hospital for delirium fulfilling the same inclusion and exclusion criteria during preceding years. The main outcome measures were duration of community care, the use of long-term institutional care, the use of short-term hospitalizations during the follow-up, and the death of the patients. Results: Delirium even in the healthy community-dwelling subjects indicated a poor prognosis. After 3 years, 18 patients (35%) from the intervention group and 9 patients (18%) from the controls were in community care. The mean duration of community care was 671 days in the intervention group and 503 days in the control group, p = .025. A reduction of 19 years was achieved in the cumulative time spent in long-term institutionalized care. The use of short-duration hospitalization was similar in both groups. Conclusion: The institutionalization of elderly patients after a delirious state could be delayed using rehabilitation periods and systematic intervention with the case manager concept.