This paper explores economic, political, and practical issues that arise in the design of environmental taxes. The observed dearth of Pigouvian taxes may result from perceived political or practical problems in the design of such taxes. The author provides a taxonomy for assessing design issues: (1) what is taxed; (2) who is to pay; (3) how large is the tax; and (4) accommodations for ancillary policy concerns. He uses this taxonomy to address issues of design to achieve economically efficient and administratively feasible outcomes. The author illustrates these points with discussion of the recently enacted excise tax on ozone-depleting chemicals.