Résumé : Purpose and Methods: The severity and prognosis of various acute inflammatory conditions, such as sepsis, differ between males and females. The mechanisms underlying these sex differences probably involve both hormonal and genetic factors. In order to evaluate a possible genetic influence, we reviewed clinical signs and biological inflammatory markers of prepubertal children with severe sepsis admitted to the pediatric intensive care unit (PICU). Findings: A total of 142 prepubertal children, 66 girls and 76 boys, suffering from severe sepsis and admitted to the PICU were included. The survival rate demonstrated a tendency to be higher in females (P = 0.14). Maximum white blood cell count (23,800 cells/mL [15,110'34,600] in girls vs. 19,025 cells/mL [12,358'26,098] in boys, P = 0.02), neutrophil count (16,944 cells/mL [10,620'27,540] vs. 13,756 cells/mL [8410'20,110], P = 0.03), and C-reactive protein level (26.2 mg/dL [15.7'33.6] vs. 18.8 mg/dL [11.1'30.0],P = 0.04) were all significantly higher in girls. Girls also exhibited significantly longer fever duration (2 days [1'6] vs. 1 day [1'3] for the boys, P<0.01), lower pH on admission (7.32 [7.25'7.39] vs. 7.37 [7.31' 7.43] P = 0.03), and lower base excess (-6 mEq/L [-10.7 to -0.8] vs. -2.3 mEq/L [-6.6 to -2.6], P <0.01), as well as lower bicarbonate levels (19.1 mEq/l [15.9'24.0] vs. 21.15 mEq/l [18.3'26.68], P = 0.04), when compared with the boys. Conclusions: Our study revealed higher neutrophilic inflammation, as well as lower pH on admission, in girls with severe sepsis; associated with longer fever duration, which could contribute to better pathogen clearance. However, further studies are needed to demonstrate the link between acidosis and modulation of the immune response.