Nitrogen dioxide (NO2) becomes one of primary variables in several studies to determine its effect on the occurence of Infants with Low Birth Weight (LBW). This study aimed to analyze the association of NO2 exposures in ambient air with the occurrence of babies with LBW in Palembang City using case-control design involving 45 cases and 45 controls. Data of ambient air quality were from the Environment Agency of Palembang including NO2 and co-pollutants (SO2, CO and PM10). Other data were certain information obtained from interview with respondents. Quantitative data were analyzed by chi-square and multiple logistic regressions. The study revealed that NO2 exposures in ambient air during the first trimester associated with the occurrence of LBW (OR: 2.74: 95% CI: 1.16-6.45). Third trimester pregnancy was also associated with the occurrence of LBW (OR: 6.01: 95% CI: 2.29-15.70). The NO2 exposures in ambient air in the third trimester of pregnancy was the variable that mostly affects the babies with LBW after controlled by the CO and PM10 exposures at first trimester; the exposures of SO2, CO and PM10 at second trimester; concomitant diseases during pregnancy; mother's age at the time of pregnancy; mother's nutritional status during pregnancy; second-hand tobacco smoke; and exposures of indoor air pollution during pregnancy (OR: 11.51; 95% CI: 2.02- 65.79).