Secondary educators must be knowledgeable in their content while increasing the academic literacy of their students, a process further complicated when working with students who are long-term English learners (LTELs). This mixed-methods study explored the knowledge, practices, and perceptions of six secondary teachers working to develop the academic literacy of LTEL students in content-specific classrooms. Set within a sociocultural framework, the study provides a greater understanding of the challenges and successes educators experience when working at the secondary level with students with diverse learning needs. The data were collected in two phases. Phase I included a quantitative survey of teachers, designed to acquire demographic information from participants who met the inclusion criteria: educators who taught a content-specific course and had a minimum population of 10.7% LTEL students in at least one of their classes. These data were analyzed using descriptive statistics. Phase II consisted of qualitative one-on-one interviews, classroom observations, and follow-up interviews. Data analysis for Phase II included transcribing the interviews and taking notes on emerging themes. Qualitative data were also provided by the classroom observations using the Observation Protocol for Academic Literacies. Notes created in each of the classrooms were coded by themes and used in the creation of profiles for each educator. Themes that emerged through the one-on-one interviews and classroom observations were used to create questions for the follow-up interviews. Findings add to the body of research regarding content-specific secondary teachers’ knowledge and perceptions about the academic literacy development of their LTELs.