The aim of this study was to provide an updated review of dental procedures undertaken at the dental unit of the Onco-hematology service of the Instituto da Criança at the Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (ICr/HC-FMUSP). We retrospectively reviewed 565 of 1902 medical and dental records of patients diagnosed with onco-hematological diseases who were seen in a 3-year study (January 2015 to December 2017). We assessed data regarding population characteristics, onco-hematological diagnosis and dental procedures performed. Of the selected medical records, preventive dentistry was the most common procedure undertaken in this population, followed by oral maxillofacial surgeries, restorative dentistry and oral mucositis treatment. The most prevalent malignant diagnosis was acute lymphocytic leukemia, and the most prevalent nonmalignant diagnosis was sickle-cell anemia. Preventive dental procedures represent most of the dental procedures undertaken in hospitalized onco-hematological pediatric patients.