This study investigates the motivating and demotivating factors influencing teachers engaged in Content and Language Integrated Learning (CLIL) at the Banking Academy of Vietnam. Employing a qualitative research design, in-depth interviews were conducted with five CLIL instructors to uncover intrinsic and extrinsic motivational elements. The Self-Determination Theory (SDT) framework was applied to analyze the findings, revealing a complex interplay of autonomy, competence, and relatedness in shaping teacher motivation. The results show the necessity for institutional support and professional development opportunities to enhance CLIL implementation and teacher satisfaction.