What is the status of empirical contributions to bioethics, especially to clinical bioethics? Where is the empirical approach discussed in bioethics related to the ongoing debate about principlism versus casuistry? Can we consider an integrative model of research in medical ethics and which empirical methodology could then be valuable, the quantitative or the qualitative? These issues will be addressed in the first, theoretical part of the paper. The concept of the "embedded researcher" presented in this article was stimulated by the two questions, (1) how can we safeguard that our research will yield valid and meaningful results to practice? and (2), how can we convince clinical colleagues that medical ethics offers relevant contributions to the analysis and solution of problems? One tentative answer has been our effort to elaborate a coherent methodological research approach in the field of end-of-life issues integrating qualitative and quantitative as well as casuistic methodologies. This development is characterized in the second part describing the ECOPE Study (short title) "Ethical Conditions Of Passive Euthanasia." The achievements and limitations of the suggested approach of the "embedded researcher" are discussed referring to 3 examples of our joint studies about ethical issues concerning (1) critical decision-making in neonatology (2) limitation of treatment in intensive care (3) problems with doctor-patient conversation at the end-of life in oncology. Conclusions from our studies are put to discussion in the final part of the paper about how to further develop research in the field of end-of-life care and, maybe, clinical bioethics as a whole.