This article describes how ethical guidelines have been applied while interviewing psychiatric patients who were recovering from mental illness, especially from psychosis, to allow nurses to understand these patients’ experiences. Because psychiatric patients are vulnerable, their participation in research involves ethical dilemmas, such as voluntary consent, legal capacity to consent, freedom of choice, and sufficient knowledge and comprehension. The first part of this article describes the most important ethical guidelines concerning human research. These have been published by different organizations, departments, (...) committees and commissions for the purpose of protecting human rights and dignity whenever research participants are vulnerable persons or their capacity to consent is limited. At present, however, no special regulations govern research involving adults who have been diagnosed with a condition characterized by mental impairment. Furthermore, a relatively small body of research has documented the effects of various disorders on decision-making capacity per se. One basic moral and policy question is whether these individuals should ever be involved in research. The second part of this article concentrates on how the investigator made sure that participating patients had understood their role in this particular piece of nursing research. During the interviews the investigator noticed that some ethical dilemmas required further study and debate because of the lack of consensus on the proposed regulatory provisions on research involving institutionalized persons and their ability to make an informed and voluntary decision. (shrink)