BACKGROUND Methemoglobinemia represents an uncommon but potentially serious cause of presentation to the emergency department, resulting in hypoxemia and even death. The symptoms and clinical findings in this condition can be nonspecific and therefore methemoglobinemia can be easily missed if the clinician is not familiar with it. This report presents a case caused by recreational drug use which has rarely been documented previously. METHODS A 23-year-old male with a history of asthma presents to the emergency department for an episode of syncope after inhalation of amyl nitrite "poppers". He had normal vitals other than tachycardia but was found to have nailbed and perioral cyanosis, a classic but uncommon presentation that is demonstrated in the included clinical image. He was found to have methemoglobinemia caused by his use of amyl nitrite and received supportive care but did not require methylene blue. CONCLUSIONS Emergency physicians should familiarize themselves with the classic physical exam findings in methemoglobinemia in order to identify and treat this condition promptly. While this patient had a good outcome with only supportive care and observation, his presentation and the etiology of his condition offer an important teaching point. The possibility of methemoglobinemia after recreational "popper" use should be considered when working up a patient who presents with cyanosis and hypoxemia.