Abstract:Introduction: Pneumonia is still a global health problem especially in developing countries because it is the leading cause of death in children aged under 5 years old. In Indonesia the incidence of children pnemonia is still high. Material and methods: The risk factors of pneumonia studied consist of house temperature, lighting, house humidity, occupancy density, exposure to cigarette smoke, and family disease history. Temperature and humidity of the house were measured by heatstress monitor, room lighting was measured by lux meters, the occupancy density was measured by direct observation, exposure to cigarette smoke and family disease history were measured by questionnaire. Data analysis using odds ratio and chi square. Conclusion: Room lighting and exposure to cigarette smoke is a major risk factor for the occurrence of pneumonia in children aged under 5 years in Samarinda, the incidence of pneumonia is significantly related to house humidity and occupancy density.