Acute viral bronchiolitis (AVB) is a common disease found throughout the world. Various aspects of it are being studied: its epidemiology, diagnosis, prognosis and treatment. Most of these studies are being conducted in developed countries, with only a few taking place in developing countries. Risk factors such as poor nutrition, an adverse environment and early weaning should be studied where these features are common. Treatment aspects such as cost-effectiveness in low income settings need further study. Use of ribavirin and respiratory syncytial virus (RSV)-immunoglobulin are good examples. Post-bronchiolitic sequelae also need to be studied in low income countries. There is evidence that bronchiolitis obliterans is unusually frequent in some Latin-American countries such as Argentina and Brazil. It will be helpful to undertake combined studies in countries with the same socio-economics, investigating the preventive and management aspects of AVB and its sequelae to reduce the morbidity and mortality.