The topicality of the research lies in the fact that there is some discrepancy between the demands of the technical workforce market and the pure linguistic approach ESP teachers usually take in teaching practices. Thus, language studies sometimes lack interdisciplinary issues. The aim of the research is to observe and compare the existing interdisciplinary methods and approaches, decide which of them are the most appropriate in the context of teaching ESP and assess the application of the methods in the classroom through students' feedback and teacher's observation techniques. The paper focuses on such didactic issues as teacher's participation in students' activities, students' autonomy, professional competencies development, motivation, and adequacy of language input in problem-based assignments. Except research in methodological approaches in ESP studies, the paper also presents a sociological perspective expressed as qualitative and quantitative results. The experiment on application of problem-based assignments proves their relevance to ESP studies. As a result, students' motivation and autonomy as well as professional aspects of communication are enhanced. As for language input, thematic correspondence and vocabulary extension largely improve students' subject-specific knowledge and skills. Grammar and phonetics were found to be weak points of language studies and are to be more proficiently integrated into such tasks. In general, the method of problembased assignments described and evaluated in the article has proved its in-built interdisciplinary nature and positive impact on students' professional activities and learning strategies.