We examined how infusing an inquiry-based Disciplinary Literacy Project (DLP) into a graduate literacy education class influenced elementary teachers' knowledge about disciplinary literacies and how this knowledge influenced their instructional practices. Through the DLP, teachers in this study developed an awareness of the nuances of the literate practices within particular disciplines and demonstrated various ways of blending this disciplinary literacy knowledge into their instructional practices. Implications include using this form of inquiry as a means for professional development and collaborating with disciplinary experts to support teachers' inclusion of discipline-specific habits of mind into their instruction.