Objective: To describe and analyze data on self-injurious behavior (SIB) and related mortality in children under 10 years old in Brazil. Methods: A descriptive study was performed using secondary public health care data extracted from the Hospital Information System (Sistema de Informações Hospitalares, SIH) and Mortality Information System (Sistema de Informações sobre Mortalidade, SIM) in Brazil. The databases are available for online access at http://datasus.saude.gov.br/. Results: In Brazil, according to SIH data, 11,312 hospitalizations of patients under 10 years of age were recorded from 1998 to 2018 as resulting from SIB (ICD-10 X60-X84 codes). Of these, 65 resulted in death. According to the SIM, from 1996 to 2016, 91 deaths related to SIB were recorded, 81 (89%) in children aged 5 to 9 years, nine (9.9%) in children aged 1 to 4 years, and one (1.1%) in a child below 1 year of age. Conclusion: These results highlight the relevance of creating measures to better understand SIB and related mortality in this age group. They also reveal the vulnerability of children in Brazil and warrant further studies to address these issues.