A prospective study was conducted to describe some epidemiological and risk factor characteristics of Cytomegalovirus associated pneumonia in children who hospitalized in the National Hospital of Pediatrics in Hanoi from 1/2010 to 12/2012. Among 427 pneumonia patients by the standards of the World Health Organization (WHO) aged 1 months to 15 years. Results showed that 246 patients were diagnosed with Cytomegalovirus associated pneumonia (57.6 percent), aged 2.5 +/- 2.2 months. This disease mostly appeared in children from 2 to 6 months of age (60,89 percent). Neonatal jaundice, a long duration of illness history and mix feeding are risk factors of Cytomegalovirus associated pneumonia (p0,05).