The use of computer software to help students’ written work in the EFL classroom has emerged as a significant way to address the language learning within the last decade. This paper discusses the application of a computer assisted genre-based pedagogy in a middle school, the contribution to students’ written work and the characteristics of the students’ written argumentative texts, pedagogy perception of both teacher and student, benefits and difficulties of combining CALL and genre-based pedagogy for the development of writing skills and the characteristics of the methodology implemented. This research project was carried out at La Enseñanza School which is a private and catholic institution located in the northern part of Barranquilla, the chosen group was tenth grade. The research was based on needs analysis which was carried out in the first stage of the study to identify students’ difficulties in the language. In the second stage, a qualitative method was selected which was action research and the techniques to collect the data were through the implementation of class observations, students’ interviews, students’ and teacher’s journal, and students’ artifacts. Students considered that the applied methodology was dynamic and it helped them in term of participation, concentration, motivation and collaborative work. Also, they wrote better argumentative texts compared to the students in the first stage. The analysis of the application demonstrated that students use the CALL resources to approach their language learning and support their argumentative text recognition and work. Our research highlights the relationship between genres and technologies.