Facing the generational challenges, such as searching for new medicinal products and methods of therapy of diseases, there are more and more questions about the ethics of research and patient safety. With the development of science, the number of clinical trials in which new products are being tested is growing. Conducting clinical trials is the only reliable way to determine whether a new cancer treatment method is more effective than the methods used so far. Pharmacovigilance of research is necessary in oncology because the phenomenon of incomplete reporting is particularly important in this area due to the high toxicity of chemotherapy treatment. In the search of current scientific evidence, the following databases have been consulted: Medline (PubMed), Embase (via OVID), as well as the Cochrane Library database. Based on the scoping carried out, significant elements were identified that were included in the search. The aim of the article is to present the safety issues of an oncological patient participating in a clinical trial. The basic terminology, legal and institutional norms regulating safety in clinical trials, reporting and monitoring methods, as well as the issue of common terminological criteria for adverse events, are discussed. There are also several groups of patients in oncology who need special attention, also in the field of pharmacovigilance. Particular attention is paid to the need to educate medical staff and patients and the role of a clinical pharmacist in a therapeutic team.