In this study, we investigated the impact of teaching socioscientific issue-based science activities using the argumentation method on the cognitive abilities of elementary school students. The study comprised a total of 63 eighth-grade students, with 32 in the experimental group and 31 in the control group, all attending a state school under the Ministry of National Education. Employing a quasi-experimental design with a pre-test and post-test control group, participants were selected through convenient sampling. In the experimental group, students engaged in activities centered around argumentation scenarios, while the control group received traditional lectures and in-class activities. The activities for the experimental group were designed in accordance with the Toulmin argumentation model. Data collection relied on three scales: attitudes towards socioscientific issues scale developed by Topçu (2010), the reflective thinking scale created by Yıldırım (2012), and the critical thinking scale by Görücü (2014). The study's findings indicated that the control group students' attitudes towards socioscientific issues demonstrated positive changes, although there was no significant enhancement in their critical thinking and reflective thinking skills. In contrast, the experimental group students exhibited significant improvements in their attitudes towards socioscientific issues, reflective thinking abilities, and critical thinking skills. These results underscore the potential benefits of incorporating socioscientific issue-based science activities more extensively in the classroom, offering students a more comprehensive educational experience.