Definition of the problem Open access (OA) publishing in medical research has been heralded as a means of democratizing knowledge dissemination by removing paywalls and allowing unrestricted access to scientific findings. However, the prevalent model of paid open access, which requires authors to pay article processing charges (APCs), raises profound ethical concerns. These concerns include financial barriers for researchers from low-income institutions, potential conflicts of interest due to the commercialization of scholarly publishing, and threats to scientific integrity posed by predatory journals. Additionally, open access raises challenges in data protection and privacy, particularly in the medical field, where patient confidentiality is paramount. Arguments and conclusion This review explores the ethical dimensions of paid open access in medical research. First, it highlights how APCs create economic disparities, limiting the ability of underfunded researchers to contribute to and benefit from scientific discourse. This perpetuates a cycle of exclusion and marginalization in global research communities. Second, it examines the potential conflicts of interest introduced by the APC model, wherein publishers may prioritize revenue generation over academic rigor, thereby weakening the peer review process. Predatory journals exploit these vulnerabilities, further eroding trust in scientific publications. Third, the ethical implications of open access in terms of data protection and citation bias are discussed. While OA articles generally receive higher citation rates, financial constraints may influence which studies gain visibility, distorting the perceived importance of research findings. To address these ethical challenges, the academic community must develop equitable funding models that ensure fair access to publishing opportunities regardless of financial means. Strengthening editorial oversight, enforcing stringent peer review standards, and promoting ethical data-sharing practices are essential to maintaining the credibility and integrity of medical research. Ultimately, while paid OA contributes to the broader dissemination of scientific knowledge, its ethical implications must be carefully managed to prevent the reinforcement of structural inequalities and to uphold the principles of academic integrity and fairness.