Respiratory syncytial virus (RSV) infection during infancy causes enormous mortality in the developing world. However, a good proportion of the mortality data have been derived from studies measuring excess mortality during RSV epidemics. Much of RSV-related deaths probably occur in the community due to lack of access to care. To understand individual characteristics of community-based and hospital-based deaths a prospective multicentre study was performed in Argentina. In hospitalized patients, case fatality was 0.9%. RSV infection explained about 50% of all deaths among infants presenting with lower respiratory tract illness. Death was related to bacterial sepsis and pneumothorax. This study is one of the first to provide insight into clinical characteristics of children dying from RSV and the mechanisms eventually preceding death.