Abstract: Pneumonia is the number one cause of death in children under five in Indonesia. South Kalimantan Province occupies fourth with the case of 66,72% and Banjarmasin City has recorded the highest incidence of pneumonia in children under five as many as 2.587 cases. The incident of pneumonia influenced by various factors, including environmental sanitation conditions and behaviour. This study aims to determine the relationship between risk factors of the physical environment of house and behaviour with the incidence of pneumonia in children under five in Banjarmasin CityThis study was an analytic observational with a case-control study.