Clinical studies should be performed before a drug is to be administered to a wider population. Each clinical trial is a carefully planned, in order to prove the effectiveness of the drug, but also to point out its harmful effects. As the clinical trials is conducted on humans it must be in accordance with good clinical practice, which is defined by internationally recognized and accepted ethical and scientific standards for the planning, implementation and monitoring of clinical trials. The same ethical and legal principles that apply to medical practice are also valid in clinical trials. However, these principles are stringently controlled by international and national laws and regulations, all aimed at the highest level of protection of the rights and safety of patients, where the safety of patients is placed in front of science. Each individual who participates in a clinical trial should be qualified, educated, trained and experienced in performing the tasks assigned to him/her in the study. The nurse is an indispensable member of the team which conducts clinical trials. However, their role was not sufficiently recognized, and there is little evidence about it. Thus, this paper aims to emphasize their role and participation in clinical trials in order to ensure this role in this area of nursing care. The competence of nurses in clinical trials is unquestionable, but needs more evidence through the publication of works that will speak in favour of it.