Atrioventricular block (AVB) is a rare complication of rheumatoid arthritis (RA). Complete AVB in people with RA significantly increases cardiovascular morbidity and doubles the mortality risk. We report on a 48-year-old woman presenting with dyspnea and peripheral edema, with symptoms of polyarthritis for 3 years. Physical findings included bradycardia, bilateral rales, and finger deformities consistent with RA. Electrocardiography featured complete AVB, and a thoracic computed tomography scan showed a mosaic appearance with fibrosis, bronchiectasis, and partial atelectasis of the lungs. Further tests showed elevated levels of C-reactive protein, rheumatoid factor, and several inflammatory cytokines. Transient followed by permanent pacemaker placement was performed along with pharmacological treatments, including intravenous (IV) methylprednisolone pulse therapy and IV tocilizumab. Cardiac involvement in RA usually takes the form of pericardial effusion, heart failure, myocarditis, and coronary artery disease. Complete AVB is a rare but important extra-articular involvement in RA that warrants early recognition and treatment with a pacemaker, anti-inflammatory drugs, and disease-modifying antirheumatic drugs. © 2025, Indonesian Society of Internal Medicine. All rights reserved.