Although the importance of students' argumentative peer feedback for learning is undeniable, there is a need for further empirical evidence on whether and how it is related to various aspects of argumentation-based learning namely argumentative essay writing, domain-specific learning, and attitudinal change while considering their epistemic beliefs which are known to be related to argumentation. In this study, a pre-test-post-test design was conducted with 42 higher education students who were asked to write an argumentative essay on the GMOs, engage in argumentative feedback, and revise their essay. The results showed that argumentative peer feedback improves students' argumentative essay writing and domain-specific learning. Furthermore, argumentative peer feedback caused attitudinal change. However, findings did not prove any impact of students' epistemic beliefs on argumentation-based learning. This is against broadly shared theoretical assumption that argumentation-based learning is related to students' epistemic beliefs. We discuss these results and provide an agenda for future work.