Background: Research ethics involve requirements on daily work, the protection of dignity of subjects and the publication of the information in the research. However, when nurses participate in research they have to cope with three value systems; society; nursing and science which may be in conflict with the values of subjects, communities, and societies and create tensions and dilemmas in nursing. Method and material: Using the Medline and the Nursing Cinahl data base, the most important ethical issues which appear in bibliography, will be addressed. After a short description of the nature of nursing, and the advocacy role of nurses, the writer will attempt to highlight the possible conflicts that nurses have to deal with, when undertaking or participating in research. Results: The major ethical issues in conducting research are: a) Informed consent, b) Beneficence- Do not harm c) Respect for anonymity and confidentiality d) Respect for privacy. However, both the nature of nursing which focuses on caring, preventing harm and protecting dignity and the advocates role of nurses which calls for defending the rights of subjects, are sometimes incongruent with the ethics in research. Conclusions: Ethical issues, conflicting values, and ambiguity in decision making, are recurrently emerging from literature review on nursing research. Because of lack of clarity in ethical standards, nurses must develop an awareness of these issues and an effective framework to deal with problems involving human rights.