Although studies have addressed high school English language arts (ELA) instruction, little is known about the decision-making process of ELA teachers. How do teachers decide between the resources and instructional strategies at their disposal? This study focused on two monolingual teachers who were in different schools and grades. They were teaching mainstream students or English Language Learners. Both employed an approach to writing instruction that emphasized cultural mediation. Two questions guided this study: How does the enactment of culturally mediated writing instruction (CMWI) in a mainstream classroom compare to the enactment in an ESL classroom? What is the nature of teacher decision-making in these high school classrooms during English language arts instruction? Data were collected and analyzed using qualitative methodologies. The findings suggest that one teacher, who was familiar with CMWI’s principles and practices and saw students as partners, focused her decisions on engagement and participation. The other teacher deliberately embedded CMWI as an instructional stance. Her decisions focused on empathy, caring and meaningful connections. These teachers enacted CMWI in different ways to meet their students’ needs. They embraced the students’ cultural resources, used and built on their linguistic knowledge, expanded thinking strategies to make difficult information comprehensible, provided authentic …