In the post truth era the limits between facts and beliefs, science and pseudo-science seem to be quite blurred. Social media platforms, such as Facebook, provide the ideal vehicle for the widespread sharing of misinformation, by fostering the creation of “filter Bubbles” and “echo chambers”. For the purposes of our study, we analyzed Facebook posts from users’ pages and public groups over a three – month period (from September 2021 to November 2021) with a primary focus on the vaccination against COVID-19. Using thematic content analysis, we attempted to explore the major themes that skeptics of COVID-19 vaccines use to justify their hesitancy. According to research findings, the anti-vaccination discourse on Facebook platform in Greece combines features such as mistrust towards politicians, the medical community, the legacy media, the establishment as a whole, and facts regarding the safety/complications of COVID-19 vaccination itself. If the medical society aspires to combat misinformation regarding health issues, then, deconstructing the anti-vaccination rhetoric will be a pivotal step for the ultimate survival of epistemological truths and scientific discourse in the public sphere.