In the past two decades, rapid population and economic growth on the U.S.–Mexico border has spurred a dramatic increase in electricity demand. In response, American energy multinationals have built power plants just south of the border that export most of their electricity to the United States. This development has stirred considerable controversy because these plants effectively skirt U.S. environmental air pollution regulations in a severely degraded international airshed. Yet to our knowledge, this concern has not been subjected to rigorous scrutiny. This paper uses a suite of air dispersion, health impacts, and valuation models to assess the human health damages in the United States and Mexico caused by air emissions from two power-exporting plants in Mexicali, Baja California. We find that these emissions have limited but nontrivial health impacts, mostly by exacerbating particulate pollution in the United States, and we value these damages at more than half a million dollars per year. These findings demonstrate that power-exporting plants can have cross-border health effects and bolster the case for systematically evaluating their environmental impacts.