This chapter reviews literature relevant to assessment of critical thinking, including several standardized tests of thinking designed for college students. It reviews advice from authorities on how to assess critical thinking in open-ended formats. The chapter describes several methods of assessment that are useful either within a course and/or for periodic evaluation of student achievement. A survey of Association for Education in Journalism and Mass Communication members revealed that most respondents agreed that teaching critical thinking is important in journalism and mass communication. The research literature on assessment of instruction in critical thinking reveals some of the strengths and weaknesses of various operational definitions of critical thinking. Assessment of critical thinking within a media education program might use a “value-added” approach in which students coming into the major are tested for critical thinking and given posttests as they complete the major.