BACKGROUND: Psychotropic drug changes during medical hospitalizations may lead to psychiatric and medical readmissions. METHODS: One-year hospitalization records of nursing home patients with chronic mental illness and a psychotropic drug change during medical admission were reviewed. We calculated the readmission rates for 30, 60, and 90 days; the classes of the psychotropic drugs changed; the reason for change; and the specialties of the responsible physicians. The readmission rates were compared with those of an age-matched control group. RESULTS: The changes were associated with an increase in psychiatric read¬mission rates of 2.7% (30 days), 5.4% (60 days), and 14.9% (90 days). The 90 days readmission rate reached statistical significance (14.9% vs 2.7%; OR = 6.29; P = .020). The family practice team was responsible for the high¬est psychiatric readmission rate (18.4%). The most significant reasons for change included human errors (up to 40%), which is alarming. CONCLUSIONS: Judicious changes, attempts at re-titration, and appropriate documentation of reasons for change on discharge records may reduce the readmission rates.