People who have had a stroke face high risks of cognitive impairment, anxiety, and depression. Health education for family members contributes to better outcomes in various diseases, but the effects of health education on family members of people who have had a stroke are unclear. The aim of the present study was to evaluate the effects of the family member education program (FMEP) on cognitive impairment, anxiety, and depression in persons who have had a stroke. In total, 144 persons who experienced a stroke were randomly allocated to the FMEP group or control group (1:1 ratio). In the FMEP group, the FMEP and conventional treatment were provided, while in control group only conventional treatment was provided. The increase in the Montreal Cognitive Assessment (MOCA) score from baseline to 12 months (M12 – baseline) in the FMEP group was higher compared with the control group, and the FMEP led to a decreased cognitive impairment rate (MOCA score ≤26) after 12 months compared to the control group. Changes in the Hospital Anxiety and Depression Scale anxiety and depression score (M12 – baseline) decreased in the FMEP group compared with the control group. Fewer participants with depression and a lower depression grade were observed in the FMEP group compared with the control group. The FMEP could reduce cognitive impairment, anxiety, and depression in persons who have had a stroke.