Introduction: The use of drugs that modulate the immune system during paediatric severe sepsis and septic shock may alter the course of disease and is poorly studied. This study aims to characterise these children who received immunomodulators and describe their clinical outcomes. Methods: This is a retrospective chart review of patients with severe sepsis and septic shock admitted into the paediatric intensive care unit (PICU). Clinical, haematological and outcome characteristics of patients with or without exposure to immune-modulating drugs were compared. Primary outcome was PICU mortality; secondary outcomes were 28-day ventilator-free days (VFD) and intensive care unit-free days (IFD). Univariate and multivariable analyses were performed for these outcomes. Results: A total of 109 patients with paediatric severe sepsis or septic shock were identified. Of this number, 47 (43.1%), 16 (14.7%) and 3 (2.8%) patients received systemic corticosteroids, intravenous immunoglobulins and granulocyte colony stimulating factor, respectively. Patients who received immune-modulating drugs were more likely to require invasive ventilation (38/54 [70.4%] versus 26/55 [47.3%], P=0.019) compared to those who did not. PICU mortality was indifferent between the 2 groups (20/54 [37.0%] vs 11/55 [20.0%], P=0.058) even after accounting for chronic complex conditions and admission organ dysfunction (PELOD score) (adjusted odds ratio 1.90, confidence interval [0.72–5.01], P=0.193). However, VFD (19.5 [0–28] vs 25 [12–28] days, P=0.038) and IFD (15 [0–24] vs 22 [9–26] days, P=0.024) were decreased in the immunomodulator group compared to the non-immunomodulator group. Conclusion: Immune-modulating drugs were frequently used in paediatric severe sepsis and septic shock. Patients who received these drugs seemed to require more PICU support. Further studies are required to examine this association thoroughly. Keywords: Children, immunomodulatory drugs, infection, paediatric intensive care unit, sepsis