We describe a case of unintentional poisoning from Ruta Graveolens, a medicinal herb that is used for heart protection in Taiwan. A 78-year-old woman developed bradycardia, acute renal failure with hyperkalemia, and coagulopathy after three days of consuming a decoction made from Ruta Graveolens for the treatment of palpitations and heart protection. She was treated with hemodialysis in the emergency department for hyperkalemia. Her bradycardia and hypotension improved gradually three days later. Ruta use might cause multi-organ toxicity. We believe this case report helps in the recognition of the systemic toxicity of Ruta Graveolens.