This study attempted to examine the extent to which training in the use of the Toulmin model of argument (TMA) helped students develop their critical thinking abilities in Egyptian EFL classrooms. The pretest-posttests control group design was employed for the intervention stage, with participants being divided into experimental (EG) and control groups (CG). The participants were 80 students from the Department of English Language and Literature, Faculty of Arts, Menoufia University who voluntarily participated in this study. Both groups were given a pretest before the experiment in which they were required to present arguments while debating, followed by a posttest after the ten weeks of treatment administration. A rubric was used by two raters and the researcher to score the speech arguments of the participants in the pre-and posttests. The results of the data analysis revealed that, in terms of their critical thinking ability, the experimental group outperformed the control group significantly.