We measured meteorological parameters and environmental concentrations of hydrogen sulfide (H2S) and criteria pollutants at Cerro Prieto, Mexico, from May to July 2010. In addition, non-condensable gases from vent stacks at Cerro Prieto geothermal power plant were sampled and analyzed by gas chromatography-mass spectrometry. A dispersion model, which was validated with environmental measurements, was applied to H2S. Criteria pollutants never exceeded the Mexican air quality standards. Results from dispersion modeling were compared against measured concentrations showing acceptable agreements for Chi square goodness of fit (chi(2)) in the 95% significance level (alpha = 0.05), at afternoons and evening events when boundary layer is decreasing and wind speed is less than 5.5 ms(-1). Determination coefficient of curve fitting for computed concentrations at less than 4 km from the source was 0.513 and farther 0.568. This study was the first to measure criteria pollutants and H2S in Cerro Prieto area. (C) 2012 Elsevier Ltd. All rights reserved.