Aims To evaluate a family-focused intervention for patients with atrial fibrillation (AF) in addition to conventional care and to establish its effect on health-related quality of life (HRQoL), anxiety, depression, AF symptoms, and family support. Background AF is a widespread heart disease affecting the well-being of patients and their family members physically and psychologically. Supporting patients and their family members could potentially facilitate regaining family strength and improve HRQoL. Methods Patients with newly diagnosed AF were randomised to standard care or additional familyfocused intervention with change in global score of the Atrial Fibrillation Quality of Life Questionnaire (AFEQT) as primary outcome after six months' follow-up. Secondary outcomes included the Hospital Anxiety and Depression Score, the European Heart Rhythm Association score, the Ice Expressive Family Functioning Questionnaire, and the Ice Family-Perceived Support Questionnaire (ICE-FPSQ). Results Sixty-eight patients received standard care (n = 35) or family focused intervention (n = 33). The median change at the six-month follow-up on the global AFEQT score was 4.17 (-1.46-9.17) in the control group and 5.83 (-2.5-30) in the intervention group, yielding a median difference of-1.67 (p = 0.500). Change in ICE-FPSQ showed significant positive scores in favour of intervention (p < 0.001); other secondary outcome changes were non-significant. Conclusion The family-focused intervention had a small positive but non-significant effect on HRQoL compared to standard care. To address the impact of AF on the patients and family members seems to improve anxiety and depression scores and perceived family support.