Background: Biomedical research nowadays is increasingly carried out in multinational and multicenter settings. Due to disparate national regulations on various ethical aspects, such as informed consent, there is the risk of ethical compromises when involving human subjects in research. Although the Declaration of Helsinki is the point of reference for ethical conduct of research on humans, national normative requirements may diverge from its provisions. The aim of this research is to examine requirements on informed consent in biomedical research in Germany, Poland, and Russia to determine how each national regulatory framework relates to the provisions of the Declaration of Helsinki. Methods: For this analysis, we conducted a search of the legal databases “Gesetze im Internet” for Germany, “Internetowy System Aktow Prawnych” for Poland, and “ГAPAHT – Garant” for Russia. The search was complemented by a review of secondary literature contained in the databases Google Scholar, PubMed, Polish National Library, and eLibrary ru. We have identified 21 normative regulations containing provisions on informed consent in clinical research in all three countries. The content of these documents was systematically categorized and analyzed. Results: The normative framework in all three countries shows a strong commitment towards the core ethical principles of research envisaged in the Declaration of Helsinki. Nevertheless, provisions on informed consent vary between these three countries. The differences range from the method and language in which information should be provided, through the amount of information required to be disclosed, to the form of documenting consent or withdrawal. In the case of research on vulnerable groups, these differences are particularly visible. Conclusions: The identified differences can negatively impact the ethical conduct of international clinical studies. Attention needs to be paid that flexibilities within national regulations are not misused to undermine the protection of research subjects. Achieving global or regional legislative harmonization might prove impossible. Such lack of legal consensus reinforces the significance of the international ethical agreements.