Background: The 21st century is characterized as “the century of life sciences”, as the scientists are now able to manipulate the hereditary material of living beings. Already, genes are used for the preparation of biodegradable, artificial new materials as well as for construction products. Stem cells are a new therapeutic tool of medicine, different from what we have been using until today. Moreover, with their plasticity, they offer the possibility of replacement of cells and tissues, especially in cases such spinal cord injury, strokes, burns, heart diseases and diabetes. Aim: The main aim of the present review was to explore the possibilities offered by genetic engineering, especially in the research field of embryonic stem cells, their possible therapeutic applications, as well as the embryonic stem cell research, which raises intense ethical and legal considerations. Method and material: A literature review was performed both in Greek and international journals. Furthermore, we investigated legislative approaches and databases of biomedical studies and sites of the European Union Member States national bioethics committees. Results: Ethical and legal concepts were of utmost importance for the stakeholders involved. Furthermore, the possibilities offered by genetic engineering, especially in the field of research on embryonic stem cells were highlighted. Conclusions: The potential therapeutic applications of its use lead to an extensive reference regarding the issue of using embryonic stem cells, which creates intense ethical and legal considerations that require sustained interdisciplinary research on the best use of this new option for the good of humanity.