We develop and present an ethics case dealing with an uncertain tax position. The case can be used to assess professional ethics as part of an assurance-of-learning (AOL) plan as well as a component of a course grade. We present data on student performance on this case over a 5-year period. Students consider existing ethical frameworks to identify and frame the potential ethical ‘‘dilemmas’’ they might face in addressing whether to countenance a client’s suggest  treatment and disclosure of an uncertain tax position. In addition, students evaluate the AICPA guidance and U.S. Treasury standards on taking and reporting uncertain tax positions in the tax return and the FASB and PCAOB standards on reporting and auditing uncertain tax positions in the financial statements. The case allows faculty to assess students’ ability to frame potential ethical dilemmas when clients engage in aggressive tax behavior, to recognize with whom and with what professional reference documents they should consult when an uncertain tax position arises, and to choose among alternative actions when faced with client/ preparer conflicts