The purpose of this research was to compare two definitions and assessments of Mathematics Pedagogical Content Knowledge (PCK). As part of a larger study, nine current and future teachers took an online version of the Measures of Knowledge for Teaching (MKT)--Mathematics assessment and the Cognitively Activating Instruction in Mathematics (COACTIV) assessment. Participants answered questions that demonstrated their understanding of students' misconceptions, ability to utilize multiple representations and methods, and knowledge of materials that they may be using for instruction. The data were analyzed, and the results indicate that teachers' scores on these two tests are correlated, but that the individual areas of knowledge were not.