Our project "Chemglish- Integrated Chemistry and English Teaching" is in-service training in CLIL methodology for our teachers. The project aims to enable the teachers from two school departments, chemistry and languages, to attend and collaborate with each other at a foreign course which covers both theory and practical use of bilingual teaching of our major subject, chemistry. Our prime and long-term objective is to enhance the quality of teaching chemistry by means of using English in chemistry lessons and thus make it easier for our students and graduates to work with sources more effectively, to have better job opportunities and easier access to study abroad. At present our school participates in the Leonardo Programme (this year we are applying under Erasmus+) under which the students in the final year take part in practical training abroad (Germany). For them the good knowledge of vocational language is necessity.The existing practice at our school of integrating scientific terminology into language teaching only, has a long tradition and provides some good results. Compared with the bilingual teaching of a subject, though, it seems unsatisfactory. We believe that the most useful approach to the problem would be the participation of both subject and English teachers in the same course where they could work together on joint outcomes based on the shared knowledge of the specific needs of our school. We intend to send two pairs of teachers (one pair each year) who, on their return, would pass the newly acquired knowledge and skills on to the other colleagues in both departments. The participants among the chemistry teachers should be at B2 level.We also plan to cooparate on making some inter-department teaching materials and methodology manual.The additional positive impact would be improving subject teacher communicative competences through this course which would consequently enable their involvement in various international activities of our institution (Eco-School, international competitions, eTwinning etc.)Due to our extensive collaboration with both primary schools and universities the aquired skills could be beneficial to the university students who have their pedagogical training at our school and the chemistry teachers from primary schools we cooperate with.The goal of the English teachers will be to provide assistance to subject teachers and learn how to help integrate English into chemistry lessons.