This study addresses the lack of information about bleeding incidences, location and risk factors in children admitted to hospital. The primary objective of this study was to determine the incidence of bleeding in children admitted to hospital. Methods: In a retrospective observational cohort study, the first admittance of 13,842 children (<18 years old) to Odense University Hospital from 2015-2020 was analyzed. Bleeding episodes and the anatomical location of bleeding were identified in electronic health record (EHR) text using a combination of artificial intelligence and manual validation. The study determined cumulative bleeding incidence during admission with Kaplan-Meier analysis and the anatomical locations of bleedings in frequencies and numbers. Subgroup analyses included spontaneous and major bleeding, and bleeding during intensive care unit (ICU) stay. Results: Overall, 1869 children bled at admission and 1523 during admission. The most frequent locations of bleeding were cutaneous, internal, and gastrointestinal, comprising 70% of episodes. The cumulative incidence of bleeding during admission was 29.1% and 19.0% for any bleeding and spontaneous bleeding, respectively. Spontaneous and major bleeding occurred in 794 (6.6%) and 174 (1.5%) of children, and six bleedings contributed to death (all central nervous system bleeds). Bleedings occurred in 36% admissions complicated with ICU stay. Independent risk factors for bleeding were prematurity, hematological cancer, infection, congenital anomalies, anticoagulants, administration and ICU stay. Conclusions: The study found a high incidence of bleeding in admitted children, and fatal bleeding episodes were registered. Thus, bleeding risk shall be considered during admission of children.