Tesis para optar al grado de Magíster en la Enseñanza del Inglés como Lenguaje ExtranjeraThe objective of this action was to explore the effects of role-play-based activities on the levels of student spoken production in a large EFL grade. The study was undertaken in a in a subsidized school in Puente Alto in a 10thclass consisting of 46 students. The primary focus for this action research was centred on the relatively low levels of spoken production during the English class which has been a problem for student. To begin with, the researcher commenced investigating the nature spoken production identifying common mistakes that occur during speaking. Later, investigation on large classes was undertaking to understand common problems and useful strategies that could augment students to speak in English. In addition, role-plays research was also revised to seek for a strategy that can effectively contribute the enhancement of speaking in large classes. Finally, a holistic approach that could help in the design of the intervention was researched to teach speaking. This concern led to a qualitative research design as an action study consisted of two role-play interventions. The methods used to collect data where implemented during the first and the second intervention and consisted of questionnaires answered by students, observations and artifacts analysis. The findings indicated that role-play-based activities had an overall positive impact on the student spoken production especially on pronunciation and also on the levels of students’ engagement. In addition, role-play-based activities contributed to a higher collaborative learning as learners felt more confident when creating their role plays and speaking in the target language