BACKGROUND: Childhood bone and joint infection (BJI) ranges in severity, with the most unwell children requiring pediatric intensive care unit (PICU) support. We describe demographic and prehospital features of BJI cases associated with PICU admission and report treatment outcomes and costs for these cases. METHODS: This study includes a retrospective cohort of children ≤15 years of age hospitalized with acute hematogenous osteomyelitis or septic arthritis in Auckland between 2018 and 2023. Cases admitted to PICU were compared to non-PICU hospitalized BJI cases. Direct medical hospitalization costs, treatment type and outcomes were described up to 1 year following discharge. RESULTS: Of 563 BJI cases, 43 (8%) were admitted to PICU. PICU cases had shorter prehospital symptom duration (3.78 vs. 5.73 days, P = 0.0002). Sensitive Staphylococcus aureus was equally likely to cause disease in PICU and non-PICU cases (P = 0.86). Average hospitalization was longer (35.78 vs. 8.71 days, P ≤ 0.0001) for those admitted to PICU. Readmission and complication rates were both higher within the first year. Average cost per admission was 78,120 NZ dollars (±96,891.64) for PICU cases versus 2,219 (±01,797.33), P = 0.01 for cases not requiring PICU admission. In regression analysis, Māori ethnicity, previous history of infections and congenital conditions were statistically associated with PICU admission. CONCLUSION: In this study, children admitted to PICU with severe BJIs were more likely to have a history of congenital conditions or previous infections. Those of Māori ethnicity are overrepresented. Children treated in PICU have longer hospitalizations and experience more adverse outcomes at 1 year following discharge.