The Common Core State Standards (CCSS) require students to read and comprehend complex content texts. They specify three dimensions of a text that simultaneously contribute to text complexity across the curriculum: qualitative dimensions, quantitative dimensions, and reader and task considerations. In literacy instruction, recognizing and analyzing the qualitative dimension of a content text is the most challenging for teachers (Frey, Fisher, & Lapp, 2012). This article describes a TESOL course project to target the qualitative analysis of complex texts assigned to in-service content teachers pursuing a TESOL endorsement. Building on the definition of text complexity specified in the CCSS and drawing on the text analysis tools of systemic functional linguistics, the project requires the teachers to conduct a comparative qualitative analysis of two quantitatively comparable content texts to enhance their own understanding of text complexity in order to design effective teaching strategies to support content literacy development of English language learners. An analysis of two literary texts is presented to illustrate the breadth and depth of this project, with suggestions of teaching strategies.