This exploratory case study research was conducted with a view to exploring how teachers teaching emergent bilingual students in ESL programs can enact the principles of culturally sustaining systematic functional linguistics (CS SFL), such as critical centering, historicizing, curricularizing, teaching and learning cycle (TLC), and semantic waving in their classrooms. Two middle school teachers participated in the study and used CS SFL principles to teach their emergent bilingual students. I gathered data for the study through non-participatory observations, semi-structured interviews, informal talks with the teachers, usually right after their classes, and artifacts from teachers and students. The thematic analysis of the data demonstrated that teachers could recognize their students' ways of knowing and being by (a) translanguaging between English and Spanish seamlessly in their classrooms; (b) centering their students' lifeways, prior knowledge, and lived experiences by making them the parts of their curricula; (c) using TLC for creating dialogic interactions between teachers and students and among students; (d) positioning their students through strength perspectives; and (e) using multimodal and multi-semiotic means of communication so that their students can understand their content area knowledge and express their ideas even if their English language is emerging. The teachers faced tensions about whether to reject or perpetuate the monolingual and monocultural ideologies expressed through English language requirements that emergent bilingual students should meet in order to succeed academically. Similarly, they reported that they had challenges in preparing students for high-stakes testing and offering their support for the students sent to in-school suspension (ISS).