We report a rare case of adult human metapneumovirus(HMPV) in a healthy 32-year-old man. There was dramaticdeterioration in his condition developing pneumonia withType-I respiratory failure and encephalitis. He neededmechanical ventilation in the intensive care setting and wastreated with intravenous ribavirin. Post-extubation heremained severely physically and cognitively impaireddespite rehabilitation. Treatment of HMPV pneumonia is atpresent, still without specific antiviral therapy. ManagingHMPV-encephalitis remained supportive and challenging.More definite treatment strategies are needed.