Heroin-induced leukoencephalopathy (HLE) is a rare neurological sequela of heroin use. Heroin can be consumed through different routes such as inhalation, intravenous injection, and snorting. HLE cases have been reported via each route. However, heroin vapor inhalation has a higher rate of HLE and is also known as “chasing the dragon syndrome.”We present a 65-year-old male who came unresponsive after heroin intoxication. During the hospital stay, he developed locked-in syndrome secondary to brain damage by HLE sequelae.