The article discusses the basic principles and motives for the introduction of subject-language integrated learning (CLIL), which is an innovative approach to education with a dual focus on learning subject content and a foreign language at the same time. Special attention is paid to the methodological foundations of CLIL, such as multiple focus, authenticity, active learning, scaffolding strategy, and collaboration. The historical background of the CLIL is analyzed, as well as modern models and principles, including the 4C model (content, communication, cognition and culture). The role of language support in the successful implementation of subject-language integrated learning and the importance of interaction between linguistic teachers and subject specialists in order to achieve a holistic educational result are discussed.