This work is a literature review that seeks to summarize the role of the dentist in the care of cancer patients undergoing radiotherapy (RT) and chemotherapy (CT). Clinical guidelines, systematic reviews and relevant studies on pre-treatment assessment, prevention and management of oral complications were reviewed: mucositis, xerostomia, radiation-related caries, opportunistic infections and osteoradionecrosis. The importance of prior dental examination, removal of septic foci when indicated, oral hygiene measures, monitoring during treatment (including management of mucositis and guidance on hygiene and nutrition) and long-term follow-up to prevent late complications are highlighted.