BACKGROUND AND AIM:To analyze some variables related to the length of stay in the Pediatric Intensive Care Unit (PICU) of a cancer center in São Paulo. METHOD:Descriptive, retrospective cross-sectional study of patients admitted to an oncology hospital in São Paulo, between 2015 and 2020. Information was collected from patients' electronic medical records. RESULTS:A total of 580 patients were admitted to the PICU, 51.7% were female with a stay of five days, 42.5% were aged between 0 and 5 years, 54.1% of admissions were through the Unified Health System with a stay of five days. days, 23.6% of patients had a hematological tumor and remained in hospital for 6.5 days, 9.4% of patients died and remained hospitalized for 18.1 days. There was readmission in 9.1% of patients with a mean length of stay of 15.6 days. Of the admissions, 58.6% were clinical with a stay of 7.8 days, 8.7% coming from the hemodynamics department or another hospital with a stay of seven days. The length of stay regarding the cause of respiratory (11%) and cardiovascular (32.5%) hospitalization was five and four days, respectively. When comparing the length of stay with the PIM II, there was a weak relationship between the variables, with a value of 1.4 days. CONCLUSIONS:The variables that influenced the length of stay were the cause of hospitalization, readmission and death. The scarcity of studies in pediatric oncology populations and instruments that better quantify the mortality of this population was highlighted