Most reported cases of lower respiratory tract infection due to herpes simplex virus type-1 (HSV-1) occurs in immunocompromised patients, however there are few cases of viral infection in inmunocompentes critically ill patients (1-3). Objective: Report the case of fatal VHS-1 pneumonia in an immunocompetent patient. Case: A ten year old girl, immunocompetent, who presents respiratory symptoms and progresses rapidly to severe hypoxemia, instability and death. Lung biopsy reported Cowdry type A inclusions and the polimerasa chain reaction (PCR) was positive for HSV-1. We discuss the clinical features, diagnosis, treatment and prognosis in critically ill immunocompetent patients with HSV-1 infection in lower respiratory tract.