Ambient air pollution causes serious health problems and premature death in people. Spatial interpolation methods have been widely used to estimate the exposure of contaminants. In this study, spatial interpolation methods (inverse distance weighted, IDW and Ordinary Kriging) were employed to predict SO2 concentrations in the Bay of Quintero, Chile. Overall, the results suggest that there is uniform spatial distribution for low SO2 concentrations and an evident spatial variability for high SO2 concentrations. Spatial differences exist for high values of SO2 measurements, indicating that the south-east zone of the Bay of Quintero has a larger exposure of the SO2 contaminant. When comparing interpolation methods, Ordinary Kriging present better performance than IDW. The results of this study may help support authorities and policymakers in the implementation of environmental actions to reduce ambient air pollution in the studied zone.