India has borrowed a colonial legacy of English language education from its British colonizers. Post-Independence, education policies pertaining to the language of instruction in school education have unequivocally been supporting multilingual education. However, the policy mandates have not been translated in the same way in classroom practices. This study, situated in the complex linguistic background of the country, examines the role of teacher orientations in executing policy directives in instructional practices in multilingual science classrooms where both teacher and students speak Hindi as their home language. Among the student population, almost two-thirds have chosen Hindi as their language of instruction, while others have opted for English. In a case study, it emerged that a teacher, owing to her academic and professional expertise in the English language, with no training in multilingual science education, coupled with firm faith in the political ascendancy of the English language, preferred to conduct science instruction in English. A need to engage in extensive professional development to equip teachers with multilingual science education teaching-learning strategies is recommended.