This article examines the intervention, through the design and pedagogical implementation of two rubrics based on theory from the Content and Language Integrated Learning (CLIL) approach, to assess the oral competences in English of a group of sophomores in a content subject. The data collection and subsequent analysis included both quantitative and qualitative sources to evaluate students' oral production and linguistic awareness, and to gather information on students' opinions concerning the intervention. The findings suggest that the implementation of the instruments was successful in terms of raising students' language awareness in oral production and provided us with valuable insights regarding their perceptions of a new sort of assessment as part of their learning process.