Zoletil is a non-opioid, non-barbiturate animal anesthetic and proprietary combination of two drugs, a dissociative anesthetic drug, tiletamine, with the benzodiazepine anxiolytic drug, zolazepam. Zoletil has greater potency than ketamine. Zoletil is abused for recreational purposes, especially by people with easy access to medicine. However, in Korea, it is available over-the-counter. Here we report on a case of an 83-year-old woman who received injection of seven vials of “Zoletil 50”by her daughter and presented with an altered mental change. Her mental state was stupor and vital sign was hypotension, bradycardia. Her blood tests indicated metabolic and respiratory acidosis and hyperkalemia. She was treated with intravenous naloxone and flumazenil but was not responsive. She was admitted to the ICU and treated with supportive therapy. Her mental state showed transient recovery, however, her clinical manifestation worsened and she expired.