The CLILIRL project was originated from the need to train and motivate Italian teachers to use CLIL methodology. This method of teaching is widely spread and used all over Europe. The European Union have been supporting the use of CLIL through recommendations and official documents. In Italy the CLIL , despite clear indications, is still partially used. Teachers lack appropriate skills: language skills are insufficient, as well as technological ones. It is necessary to learn the innovative teaching methods and approaches used in other European countries in order to internationalize curricula. This project aimed to improve the quality of teaching through the mobility of 5 teachers of the Institute Marzoli in Ireland. The identification of an Irish high school with similar characteristics to the Institute Marzoli was an opportunity for comparing the two education systems. Through 15 days of Job Shadowing teachers had the opportunity to enhance their language, methodological and cultural skills. Moreover, they have given an important contribution in theri school to the development of the CLIL methodology and to the more general process of internationalization of the school. The objectives of the project were: -respect the Italian legislation which introduce foreign language lessons in the last year of high schools and technical schools; -improving and motivate CLIL teachers in their work to redesign the content and methods of teaching, the acquisition of new tools, testing new approaches and partnerships in the network; -to develop teachers’ language and digital skills to enhance their professionalism; -increase the quality of the school, by offering international educational courses - improve the opportunities given by students’diplomas at local and international levels through curricula of European studies. These objectives have been achieved. The project lasted 12 months and was divided into the following phases: - Preparation: participants selection, language and inteculturale training online, preparation of materials and an observation grid to be used during the Job Shadowing - Job Shadowing: at two different times of the school year 5 teachers attended 18 hours of classes a week in a school in Ireland for two weeks. During the same period they delivered several lessons in English to the Irish students. - Follow-up: development of three learning modules (units) per teacher with CLIL teaching, use in the classes of the new modules, building a bilingual technical glossary in support of the teaching units, creating some pages in English on the school website, presentation of the project results to the CLIL provincial network. In addition to the improvement of teaching, language and digital skills, we the project increased the motivation of teachers to use the CLIL methodology and helped them to compare with other realities, to live their profession in an international and European dimension and to invest more on their professional development. School has gained innovation in the system, got more modern and innovative curricula, the diplomas could be more employable in the labor market, and there was an increase in hours of CLIL teaching. The dissemination of the project was realized mainly through the web: pages about the project were created on the school website, and CLIL provincial network eTwinning platform. Meetings were organized with the main stakeholders: teachers of the School, groups of entrepreneurs, provincial CLIL network CLIL.