Abstract:Content and Language Integrated Learning (CLIL) provides students with enhanced opportunities to acquire competence in additional languages while learning different subjects. Due to its features one of the target subjects for the application of CLIL is Physical Education (PE). In this subject its application is widespread in countries such as Italy, Greece or Spain among others. The particular interest of this research focuses on the Spanish context. Spanish education is particularly sensitive to European initiatives regarding language policies. The aim of the study is to know, from the PE teachers' viewpoint, whether the essence of PE is subjected to so substantial modifications due to the introduction of CLIL that jeopardize its idiosyncrasy. We opt for a pure qualitative research method based on semi-structured interviews. Particularly, an a priori theoretical orientation that influenced the development of our research questions, interview protocols, and subsequent data analysis was used. The results found were organized in five categories of analysis: Curricular effects, Language insertion, Teaching method, Motivation and Workload. Furthermore, each category was broken into several subcategories. The application of CLIL within the Secondary education in Spain does not endanger the essence of the PE according to the interviewees' perception. However, the study may conclude that there is a need to improve the amount of workload and the acknowledgement of teachers involved, since it could result in an increase of burnout and demotivation.