Oncology patients belong to the risk group of patients whose treatment requires a multidisciplinary approach, and the role of the dentist is one of the most important factors in the process of treating the disease. Since patients with malignant diseases are often prescribed radiotherapy and/or chemotherapy, the numerous side effects that occur during or after therapy can lead to interruption of treatment and thus to a worsening of the underlying disease. Therefore, the presence of a dentist in the oncology team and knowledge of the patient's underlying disease, the stage at the time of diagnosis and the recommended therapy are extremely important. All dental procedures should be completed no later than three weeks before the start of therapy to allow sufficient time for tissue healing. Timely rehabilitation reduces the intensity of acute complications and the occurrence of chronic complications and improves the patient’s overall quality of life. The goal is to eliminate the need for tooth extraction in order to prevent the occurrence of the most severe chronic complication of the therapy – osteoradionecrosis/osteonecrosis, and thus jeopardize the individual’s life. Despite the recommendation that all dental procedures should be completed before starting the therapy, if there was not enough time to do so or the patient was uncooperative, it is recommended to postpone the procedures after the end of the therapy, taking certain precautions. Emphasis is placed on the patient’s motivation regarding proper oral hygiene, regular controls and compliance with recommendations during and after therapy.