Latifi's viper (Montivipera latifii), also known as Lar Valley or Damavandi viper, is endemic to Iran. It has rarely been recorded, as it occurs in a highly-protected national park. In this first clinical report of a confirmed bite by this species, a teenage girl was bitten on the chin, causing rapidly-progressive swelling of the face and oropharyngeal mucosa. At a local hospital, a misleading history given by the patient's relatives of a wasp sting and inadequate inspection of the bite wound misled the physicians from making the correct diagnosis, resulting in a considerable delay in the administration of antivenom. This allowed the development of partial obstruction of the upper airway causing respiratory distress. After transfer to a tertiary hospital, attempts at endotracheal intubation failed, necessitating tracheostomy, but this was not implemented early enough to prevent her developing respiratory failure and losing consciousness. After she was stabilized, snakebite envenoming was diagnosed by a clinical toxicologist who observed two fang puncture marks on her chin. This was later confirmed when a snake, identified as M. latifii, was discovered at the room where the bite had occurred. Her facial swelling and ecchymosis, attributable to envenoming, were effectively controlled by high-dose antivenom therapy. However, she did not recover consciousness, remaining in a vegetative state. About three weeks after the bite, she died as an indirect result of hypoxic brain damage complicated by septicemia. Prompt diagnosis, relief of upper airway obstruction and timely antivenom therapy might have prevented this tragic fatal outcome.