Pneumonia is the number one deadliest disease in the world with the prevalence of 44%. In Indonesia, pneumonia in to odler is the leading cause of death, after diarrhea, with proportion 15,5%. Pneumonia is a disease caused by a virus and bacteria influenced by physical and chemical contaminants. The purpose of this study is to analyze indoor air quality with the incidence of pneumonia in children under five years old with cross sectional method. The population in this study is the population living in the region of South Cimahi Public Health Center and Leuwi Gajah Public Health Center. The criteria of selection for the region are: region with the highest population, high pneumonia cases (in the red and yellow area), a coal-fired industrial area, and located near the toll Purbaleunyi. The sample of this research are respondents who live in the region of South Cimahi Public Health Center and Leuwi Gajah Public Health Center with inclusion criteria length of stay ≥1 year with a child under five years old. Significant correlation occur between PM10 and PM2,5 (p < 0.05) with odd ratio 4.40 and 3.24 while the density of dwelling house, room occupancy density, home ventilation, kitchen hole, a smoker in the home, use of mosquito coils, sulfur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide (CO) did not show a significant relationship (p > 0.05) with pneumonia. Dominant factors that cause pneumonia in infants is PM10 (p 0.036) with a value of OR 4.09 after controlled PM2,5 (p 0.142; OR 2.78), the number of bacteria (p 0.004; OR 0.17) and ventilation the house (p 0.395; OR 0.58).