The aim of this article is to present the issues concerning the role and constitutional position of the Supreme Bioethics Commission in the system of ethical evaluation of clinical trials in Poland. The Act of 9 March 2023 on clinical trials of medicinal products for human use (Journal of Laws 2023, item 605) changed the system of clinical trial evaluation in Poland. It established the Supreme Bioethics Commission for Clinical Trials, operating under the Medical Research Agency, but as an independent body from the Agency. The composition of the Commission is diverse and guarantees that the assessment of a trial is carried out from various perspectives: medical, ethical and legal. In addition, the Supreme Bioethics Commission acts as a coordinator of local commissions, as it evaluates applications for the inclusion of these commissions on a list maintained by its Chair. The adoption and entry into force of the Act has improved the safety of patients participating in these trials. The assessment process takes into account the opinions of non-experts representing patients or their organisations. The change in the research assessment system has meant that applications to conduct clinical trials are now assessed more effectively, transparently and within the statutory time limit.