Breast cancer is a malignant disease in women that represents a significant public health and clinical problem. The diagnosis of breast cancer itself begins with a history and clinical examination. When diagnosing, it is important to emphasize the examination that the woman does herself, which is of central importance in the early detection of the disease. Diagnosis is performed through mammography, ultrasound examination, magnetic resonance biopsy, etc. Upon learning of breast cancer, he moves on to treatment. The treatment itself requires a lot of effort in the patient from surgery, radiation, chemotherapy, hormone therapy, and immunotherapy. Treatment is started after the biopsy. The most important prognostic criterion is certainly lymph node involvement. The higher the number of lymph node metastases affected, the worse the prognosis. The health care of a patient with breast cancer is unquestionable, so health professionals, nurses-technicians have a big role in all this. The nurse-technician observes and recognizes the nurse's diagnoses, and accordingly works out a health care plan. The role of the nurse-technician is to create an intervention plan through the patient's diagnoses. The purpose of this paper is to analyze and explain nursing diagnoses and interventions in diagnostic and therapeutic procedures in persons with breast malignancy.