Among children 1-23 months of age with respiratory syncytial virus-associated acute lower respiratory infection in Botswana, young age (<6 months), household use of wood as a cooking fuel, moderate or severe malnutrition and oxygen saturation <90% on room air were independent predictors of clinical nonresponse at 48 hours. Among HIV-uninfected infants less than six months of age, HIV exposure was associated with a higher risk of in-hospital mortality.