In the 1960s and 1970s, Iranian officials embraced natural gas as a new energy source for their rapidly industrializing society, seeing it as a readily available substitute for the lucrative oil products their country's citizens were consuming in increasing amounts. Reacting to the growing concentrations of smoke and haze in cities, and unable to alter the mountainous terrain and semiarid climate that intensified them, gas seemingly promised to be a technical savior upon which to build an Iran as environmentally sound as it was prosperous, technologically sophisticated, and energy hungry. Pahlavi-era developmental choices were shaped by officials’ concern for deteriorating environmental conditions, the natural factors that compounded the issue, and the interests of private industry. Using archival and published materials collected in Iran, this article focuses on urban air pollution and the fitful efforts to mitigate it through the conversion of industrial facilities to gas.