Objective: To evaluate the association between chemotherapy and radiotherapy with occurrence of oral complications in cancer patients. Methods: This cross-sectional study included 399 adults in cancer treatment in a High Complexity Oncology Care Unit (HCOCU) in Minas Gerais, Brazil. Participants adults (> 18 years) were included in the study who undergoing treatment or are being monitored after treatment, at the Oncological Center of the Casa de Caridade Nossa Senhora do Perpétuo Socorro between 2017 and 2019. Outcomes were assessed through a questionnarie about selfreported oral complications, such as xerostomia, halitosis, taste changes, dietary modifications, trismus, mucositis, and the presence of infection/inflammation.