To raise the literacy achievement of secondary school students, some schools train their whole faculties in general reading and writing strategies to implement across the curriculum. Content-area teachers often resist this approach, however, fearing that setting aside time for literacy instruction will dilute the academic rigor of mathematics, science, and social studies courses. An alternative approach called disciplinary literacy builds students' academic content knowledge and their reading, writing, and thinking skills simultaneously. Disciplinary literacy is based on the premise that students develop deep conceptual knowledge in a discipline by using the habits of reading, writing, talking, and thinking which that discipline values and uses. This article gives detailed classroom examples of how teachers implement the five principles of the disciplinary literacy framework: knowledge and thinking go hand in hand; learning is apprenticeship; teachers mentor student apprentices; instruction and assessment drive each other; and classroom culture socializes intelligence.