As more English learners (ELs) are included in mainstream content classrooms at the secondary level, the need to understand how teachers collaborate to meet the particular instructional needs of ELs is essential. This paper presents findings from a qualitative case study that investigated the collaborative work that engaged a group of literacy teachers over the course of a school year in one culturally and linguistically diverse high school. The ongoing collaboration of the mainstream language arts teachers and English-as-a-second-language (ESL) teachers is examined, including the role of an EL facilitator/ESL teacher in supporting teacher professional learning and inclusion. The contributions and collaboration of this literacy team are described and analysed. How this collaborative work provided opportunities to grapple with meeting the instructional needs of ELs and the inclusion of both ELs and ESL teachers in the mainstream curriculum are discussed as well as implications for the field.