Aims & Objectives: It was aimed to present a severe case with multiorgan failure secondary to influenza virus. Methods: A four-year and five-month-old girl presented with a runny nose and fever. She was hypotensive and lethargic at admission and intubated because of respiratory failure. Adrenaline and milrinone infusion was because of hypotension. Clinical findings and labarotory parameters were consistent with multiple organ failure (PELOD score 51). Plasma exchange was performed by considering cytokine storm with detection of high ferritin level (3288 µg/L). Intravenous immunoglobulin was given to influenza infection by considering secondary myocarditis due to elevated cardiac markers and decreased cardiac contraction (ejection fraction 40%). Results: On the second day, continuous venovenous hemodiafiltration was started because of oliguria. After detection of influenza A (H1N1) in nasopharyngeal aspirate, oseltamivir treatment was extended to ten days. Plasma exchange was performed five times. After plasma exchange sessions ferritin level decreased to 597 µg/L and PELOD score decreased to 10. She was extubated on the eighth day. In lymphocyte subgroups, “natural killer” cells were found to be low (0%), and central ‘memory ‘T cell ratio was found to be low in lymphocyte proliferation test. A new generation sequencing panel was studied for agent-specific immune deficiency. On the 32nd day of hospitalization, she was transferred to the pediatric ward. Conclusions: In hyperferritinemic sepsis and multiorgan failure caused by influenza virus, plasma exchange and venovenous hemodiafiltration minimize mortality and morbidity.