The language policy of Bangladesh advocates the use of the national language ‘Bengali’ in all spheres of life. While English serves as a foreign language and taught as a compulsory subject in the academic domain, the dominance of Bengali prevails. As a result, the leading indigenous group known as the ‘Chakma’ has no other choice but to speak these languages regardless of having a distinct vernacular. The situation evoked the possibility of language shift by the Chakmas to Bengali which brought about this investigation. For serving the purpose, a mixed-method approach was applied through questionnaires and semi-structured interviews to know the language usage in seven major domains by the Chakmas who live in the Chattogram city and Rangamati of Bangladesh. The research outcomes portray the domination of the national language Bengali in the formal domains along with a noticeable interference of it in the intimate spheres. The Use of English turned out minimal in all domains. The findings confirmed that the Chakmas have not completely shifted their language to the Bengali. However, the presence of Bengali in the intimate domain may indicate that the coming generations who will live in the city areas will completely shift their language to Bengali. The study will draw the attention of the policymakers of Bangladesh to acknowledge the indigenous languages in the existing language policy. Besides, both the Bengali and Chakma society will be aware of the necessity of maintaining the Chakma language, which is a part of the national cultural heritage. The study will further inspire the Chakma speakers to increase their Chakma use in the social domains, especially the migrated families in the city areas.