en Original Research <span style="font-size:12pt"><span style="line-height:normal"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt"><span cambria="style=font-family:"><strong>Aims:&nbsp;</strong>Heart failure is a major global public health problem. This study aimed to assess the&nbsp;effect of a self-efficacy-based nursing intervention on stress, anxiety, depression, and quality of&nbsp;life in patients with heart failure.<br> <strong>Materials & Methods:</strong> This quasi-experimental study was conducted involving 252 participants,&nbsp;with 126 assigned to the intervention group and 126 to the control group, at community&nbsp;cardiology centers in South Sulawesi, Indonesia. The intervention group participated in a twelve-week&nbsp;structured program centered on knowledge, motivation, and self-monitoring, based on&nbsp;Bandura&rsquo;s self-efficacy theory. Psychological distress, quality of life, and functional independence&nbsp;were evaluated at baseline and during the intervention.<br> <strong>Findings:</strong> Participants in the intervention group showed significant reductions in stress (p=0.001),&nbsp;anxiety (p<0.001), and depression (p=0.001) compared to the control group. Quality of life&nbsp;improved in physical (median=63.00), psychological (median=69.00), and social (median=69.00)&nbsp;domains. Functional independence showed a significant increase (p=0.002).<br> <strong>Conclusion:</strong> The self-efficacy-based nursing intervention significantly decreases psychological&nbsp;distress and improves quality of life in patients with heart failure.</span></span></span></span></span> Heart Failure, Psychological Distress, Quality of Life 69 75 http://hehp.modares.ac.ir/browse.php?a_code=A-10-2-9378&slc_lang=en&sid=4 A. Asri asri_m.kep@stikespanritahusada.ac.id 1003194753284600380324 1003194753284600380324 Yes Community and Family Nursing Department, Panrita Husada College of Health Sciences Bulukumba, South Sulawesi, Indonesia A. SUSWANI andisuswani77@gmail.com 1003194753284600380325 1003194753284600380325 No Community and Family Nursing Department, Panrita Husada College of Health Sciences Bulukumba, South Sulawesi, Indonesia S. Safruddin safaryahya1@gmail.com 1003194753284600380326 1003194753284600380326 No Community and Family Nursing Department, Panrita Husada College of Health Sciences Bulukumba, South Sulawesi, Indonesia M. Muriyati muriyati.stikes@gmail.com 1003194753284600380327 1003194753284600380327 No Medical Surgical Nursing Department, Panrita Husada College of Health Sciences Bulukumba, South Sulawesi, Indonesia A. AB aszrulrul@gmail.com 1003194753284600380328 1003194753284600380328 No Community and Family Nursing Department, Panrita Husada College of Health Sciences Bulukumba, South Sulawesi, Indonesia