Abstract Family psychoeducation has been shown to prevent the relapse of schizophrenia. However, whether medical costs are reduced by this approach remains uncertain. The subjects were patients with schizophrenia who lived with high-expressed emotion (EE) families and were at high risk of relapse. A total of 30 patients whose families underwent psychoeducation and intensive family sessions or psychoeducation and subsequent support were regarded as the psychoeducation group. A high-EE group without family psychoeducation made up of 24 patients was used as a control group. The mean outpatient medical cost, duration of hospitalization, inpatient medical cost, and total medical cost during the follow-up period were compared between the psychoeducation group and the control group. The mean inpatient medical cost was ¥270 000 in the psychoeducation group and ¥470 000 in the control group. The mean total medical costs were ¥500 000 in the psychoeducation group and ¥710 000 in the control group. The cost in the psychoeducation group was significantly lower than the control group by Mann–Whitney U-test. The proportion of patients with a total medical cost greater than the median value was 23% in the psychoeducation group and 54% in the control group with a significant difference. The medical cost can be reduced in the psychoeducation group compared with the control group due to the prevention of re-hospitalization by family psychoeducation.