Growing numbers of English Learners (ELs) in public education are placed in a variety of second language programs across the nation. Policymakers, educators, and parents are indecisive on which programs are most beneficial for the linguistic and cultural needs of ELs. Empirical studies on two-way bilingual immersion (TWBI) programs seem to provide promising data for ELs receiving content instruction in their primary language while acquiring second language acquisition skills in classrooms where students are integrated with native English speakers. The goals of TWBI programs are for all students to become bilingual, biliterate, and bicultural. This study examined the instructional strategies teachers used to develop biliteracy and cross-cultural competence in TWBI. A single case study approach allowed the researcher to gain insights about the implementation of strategies in two TWBI programs in Southern California. The methods included multiple measures to collect and analyze the data through photo-elicitation journals, appreciative inquiry interviews, lesson observations, teacher reflections, and questionnaires. The sample population for this case study included nine bilingual teachers in TWBI programs with 90/ 10 model designs in grades first through sixth. First, the research synthesized how the teachers gained their knowledge-base and professional support to implement their strategies. Second, the findings discussed how the framework for the Guiding Principles for Dual Language Education assisted teachers in the implementation of their instructional strategies. Third, the data analysis described the successes and challenges in the teachers' instructional strategies to develop biliteracy and cross- cultural competence with ELs and English Proficient students in their classrooms. Lastly, the study discussed how the teachers gained new insights about their practices based on their successes and challenges in their strategies. Results of the study demonstrated that teachers were very experienced and knowledgeable in TWBI practices and supported each other through planning and lesson development. Teachers implemented strategies aligned to the four main guiding principles of instruction : research-based practices, instructional strategies, student-centered instruction, and multicultural/ multilingual learning environments. Convergence of multiple measures indicated that teachers experienced successes and challenges in their instructional strategies for biliteracy and cross-cultural competence, but established new perspectives and innovations to advance their practice