Respiratory syncytial virus (RSV) is the most common cause of hospitalization for acute lower respiratory tract infection, specifically bronchiolitis, affecting infants and young children. An association between primary RSV infection and childhood asthma has been suggested. Rapid and accurate diagnosis of RSV infection is crucial for appropriate patient management and infection control. The aim of our study was to compare the diagnostic performance of Binax NOW RSV (BN) as a rapid test for detection of RSV antigen in nasal wash specimens collected from Egyptian infants and young children with the detection of RSV-RNA by reverse transcription polymerase chain reaction (RT-PCR). Furthermore, to study the frequency of RSV infection in Egyptian infants and young children during the winter season 2009/2010 and the effect of certain risk factors including age and gender on the extent and impact of RSV infection. The study included 72 infants and young children, their age ranged from one to thirty six months. They were 43 males and 29 females. They were