AIMS: In this study, we implemented the Illness Management and Recovery (IMR) program for middle-aged and older patients with schizophrenia hospitalized for long periods and assessed the effect of the IMR program on psychiatric symptoms and psychosocial function. The effects of the IMR program on brain structure were also evaluated. METHODS: The IMR program was implemented for 19 patients with schizophrenia; 17 patients with schizophrenia receiving treatment as usual (TAU) were also recruited as controls. In all patients, mean age was 61.4 years (range, 50-77 years) and mean hospitalization duration was 13.1 years (range, 1-31 years) at enrollment. Structural magnetic resonance images and Positive and Negative Syndrome Scale (PANSS) and Global Assessment of Functioning (GAF) scores as clinical variables were obtained at the beginning and end of the IMR program. Longitudinal analyses were performed to compare the effects of the IMR program on clinical symptoms and cortical thickness in the superior temporal gyrus (STG) between the IMR and TAU groups. RESULTS: Significant improvements in GAF scores and the total, Insight and Judgment, and Positive components of the PANSS were found in the IMR group compared with the TAU group. Cortical thickness in the left STG was preserved in the IMR group compared with the TAU group. CONCLUSIONS: This is the first report demonstrating the effectiveness of the IMR program for improving psychotic symptoms and psychosocial function and protecting brain structure in middle-aged and older inpatients with schizophrenia hospitalized for long periods.