The article deals with the challenges of teaching ESP and EMI at Ukrainian universities, particularly during wartime. It highlights the reasons for the increased popularity of ESP and EMI, the differences between them, the importance of cross-departmental collaboration, and the challenges the instructors face. The author has proposed a four-step approach to planning an ESP/EMI lesson based on backward design, i.e. identifying learning outcomes, planning the actual lesson, identifying assessments, and reflection. The language instructors can incorporate content knowledge and skills, focus on academic language skills and students’ emergent language, and use the components of Project-based learning and Dogme approach. In addition, various models for organizing ESP/EMI classes have been suggested, particularly the following elements of a lesson: flipped learning, warming-up, mini-lecture (video lecture or reading), in-class interactive activities, and summarizing. Ukrainian teachers have to adapt to new challenges, thus restructuring the teaching process due to new wartime realia and challenges.