BackgroundThe purpose of this study was to examine the effects of a brief family psychoeducation (BFP) programme provided by psychiatric visiting nurses on caregiver burden of family caregivers of people with schizophrenia through a cluster randomised controlled trial (cRCT).MethodsThe study was a two-arm, parallel-group cRCT. Forty-seven psychiatric visiting nurse agencies were randomly allocated to the BFP programme group (intervention group) or treatment as usual group (TAU; control group). Caregivers of people with schizophrenia were recruited by psychiatric visiting nurses using a randomly ordered list. The primary outcome was caregiver burden, measured using the Japanese version of the Zarit Burden Interview. Outcome assessments were conducted at baseline, 1-month follow-up, and 6-month follow-up. Intention-to-treat analysis was conducted to examine the effects of the BFP programme on caregiver burden.ResultsThirty-four psychiatric visiting nurse agencies and 83 family caregivers of people with schizophrenia participated in the study. The participant attrition rate was less than 20%. Adherence to the program was 100%. Compared with TAU group, the BFP programme group had decreased caregiver burden. However, this improvement was not significant at 1-month follow-up (adjusted mean difference [aMD] = 0.27, 95% CI = − 5.48 to 6.03, p = 0.93, d = 0.01) or 6-month follow-up (aMD = − 2.12, 95% CI = − 7.80 to 3.56, p = 0.45, d = 0.11).ConclusionsThe BFP programme provided by psychiatric visiting nurses did not achieve significant decreases in caregiver burden. This result may be attributed to the difficulty in continuing the research due to the COVID-19 pandemic, which prevented us from achieving the targeted sample size necessary to meet the statistical power requirements, as well as to the participation of caregivers with relatively low burden. However, the program had the advantage of high adherence to treatment plan. Further studies should be conducted with a larger sample size and a more diverse sample that includes caregivers with a higher care burden.Trial registrationThe study protocol was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000038044) on 2019/09/18.