One modern definition of "corporate diplomacy" states "executives engage in the private sector version of international diplomacy... advancing their objectives through interactions with the leaders of other corporations, governments, analysts, the media and interest groups." The smog in Donora, Pennsylvania, brought the previously ignored issue of air pollution into the public spotlight and pitted environmentalists against industrialists, scientists against economists, and ordinary citizens against policymakers. The tragedy of Donora illustrates the medical, environmental, and economic consequences of the clash between public debate and corporate diplomacy in the fight for clean air. In this article, the author discusses the public debate and corporate diplomacy that clashed over air pollution--not just in regard to health issues, but also concerning the environment at large. (Contains 97 notes.)