Background: Paracetamol is considered a safe and effective analgesic, antipyretic drug that is widely used in the world. It causes significant hepatic injury and less commonly renal failure when used in excess amounts. Cardiac abnormalities is predicted to be a serious complication of paracetamol poisoning. Case: A 20-year-old female with Reynoud syndrome presented to the hospital approximately 20 hours after ingestion of 15 g of paracetamol. On admission, her respiratory rate was 8 per-minute, oxygen saturation 99% on room air, blood pressure of 147/84 mmHg, and Glasgow coma score of 13. Electrocardiograph showed 2:1 atrioventricular block and bradycardia (42 bpm). Initial bloods chemistry revealed AST 586 IU/L, ALT 516 IU/L, INR 1.27, and lactate 2.19 mmol/L. Acetaminophen level was 94.4 μg/mL (RR:10-30 μg/mL). N-acetylcysteine infusion (150 mg/kg over 20 minutes,and next 50 mg/kg every 4 hour) and fluid support treatment was started immediately after admission to the intensive care unit(ICU). Acetaminophen level was repeated after 36 h and was 17.2 μg/mL. She remained hemodynamically stable but the electrocardiograph still showed 2:1 av block (min 36 bpm). 48 hours post-ingestion subsequently developed acute liver injury with a peak ALT of 7573 U/L, peak AST of 5926 U/L, and peak INR of 2.15. Kidney function did not deteriorate at all during stay in the ICU. Hepatic functions improved from day 3, whereas AV block didn’t recover. Bedside echocardiogram showed normal systolic function. Electrocardiograph abnormality was associated with excess paracetamol overdose by the cardiology. She was discharged to the ward 7 days after admission. Cardiac and hepatic function returned to baseline, and she was discharged to hospital after 15 days. Conclusion: Paracetamol overdose and its side effects are common in clinical practice. Cardiac abnormalities such as myocarditis, ST/T wave changes, subendocardial haemorrhages and myocardial necrosis have been reported in the literature following paracetamol overdose. Our case was presented with 2:1 av block and refractory bradycardia. It is claimed that cardiotoxicity is due to metabolic disorders that can lead to arrhythmias. Although cardiotoxicity is rare following paracetamol overdose, physicians should be aware of it, and electrocardiography should be a part of daily routine. [ABSTRACT FROM AUTHOR]