BACKGROUND:To analyze early changes in white blood cells (WBCs), C-reactive protein (CRP) and procalcitonin (PCT) in children with multiple trauma, before secondary inflammation develops. METHODS:This single-center retrospective study collected data from patients with blunt traumatic injury admitted to the pediatric intensive care unit (PICU). According to the prognostic outcome of 28 day after admission to the PICU, patients were divided into survival group (n=141) and non-survival group (n=36). RESULTS:The percentages of children with increasing WBC, CRP, and PCT levels were 81.36%, 31.07%, and 95.48%, respectively. Patients in the non-survival group presented a statistically significantly higher injury severity score (ISS) than patients in the survival group: 37.17±16.11 vs. 22.23±11.24 (t=6.47, P<0.01). WBCs were also higher in non-survival group than in the survival group ([18.70±8.42]×10 9 /L vs. [15.89±6.98] ×10 9 /L, t=2.065, P=0.040). There was no statistically significant difference between the survival and non-survival groups in PCT or CRP. The areas under the ROC curves of PCT, WBC and ISS for predicting 28-day mortality were 0.548 (P=0.376), 0.607 (P=0.047) and 0.799 (P<0.01), respectively.CONCLUSIONS: As a result of multiple trauma, PCT levels increased in more patients, even if their WBC and CRP levels remained unchanged. However, early rising WBC and ISS were better than PCT at predicting the mortality of multiple trauma patients in the PICU.