Having a dual focus on teaching content information and language is important in language-learning contexts and is a defining feature of dual language bilingual education (DLBE). However, systematically teaching both language and content is challenging for DLBE teachers. This exploratory mixed methods study of nine Spanish-English bilingual Latinx preservice teachers (PSTs) placed in United States DLBE primary classrooms sought to determine how PSTs attended to language acquisition and development during content instruction. Seventy videos of PSTs teaching content-area lessons were analyzed quantitatively using a researcher-created rubric for "Integrated Language and Content and Attention to Language." Forty of these relatively high-scoring videos and transcripts were analyzed qualitatively by coding linguistic and multimodal communication to further describe PSTs' instructional moves. Findings indicate that throughout their preparation programme, PSTs improved their integration of language and content and attention to language, but their linguistic focus remained limited to vocabulary instruction. PSTs also focused more on students' receptive than expressive language development. Understanding PSTs' developing abilities to integrate content and language has implications for teacher education to support DLBE PSTs' emerging pedagogy.