This case study probed effective Language Learning Strategies (LLS) of successful adult foreign language learners who come into the classroom with their own beliefs in learning, such as the opinions about curriculum, instruction, as well as LLS. LLS is defined by Oxford (1990) as specific actions, behaviors, steps, or techniques that students use to improve their progress in developing L2 skills. LLS play a critical role in learner development. Effective LLS facilitate learners’ internalization, storage, retrieval, or use of the new language, and are essential tools for language learners to engage in self-directed learning and to develop higher proficiency level. The research revealed the findings of the case study that used triangulation of data collected from interviews and class observation to investigate LLS of three advanced-level Chinese language learners at Defense Language Institute. The author demonstrated how effective learning strategies can be acquired through learners’ efforts and awareness, be taught by teachers, and be cultivated in an optimal learning environment. The author also argued that, in foreign language classrooms, teachers have the twin goals of developing both language and learning skills. Based on the findings of the study, the author discussed why and how foreign language teachers play a pivotal role in fostering learners’ effective LLS, and provided practical pedagogical recommendations.