Oncology is a branch of medicine that deals with the prevention, diagnosis and treatment of people who have malignant disease. Malignant disease includes all conditions in which malignant tissue (cancer / tumor) occurs. Risk factors for its occurrence are numerous, and the diagnosis consists of a properly performed anamnesis, medical-diagnostic tests (primarily imaging techniques) and laboratory tests (positive presence of tumor markers). Treatment consists of 3 separate medical procedures (surgical treatment, radiotherapy and chemotherapy), and the complete curement is considered the absence of the disease in the next 5 years. The job of a nurse / technician varies depending on which part of the disease is involved in the patient's health care. Therefore, one patient will encounter a number of nurses/technicians who will be in charge of different tasks during his or her treatment. Possible health care problems arise from the primary diagnosis and depend on the degree of progression as well as the localization of the tumor. Therefore, the process of health care in such a patient is extremely extensive and therefore the paper is divided into 3 parts. The first deals with the problems of health care when a patient is committed to a hospital and his reaction to the knowledge of malignant disease, the second part shows the problems of a patient who is in the process of treatment, and in the third part we have a patient whose treatment did not give a positive effect and requires palliative care. In addition, two connected topics dealing with the main guidelines of the work were addressed at the end of the paper. First is dedicated to the pilot project of self-analysis of side effects of chemotherapy, and the second is dedicated to the mobile palliative care team of the Istrian County.