Despite recent therapeutic advances, mortality due to septic shock remains high. The most important causes of mortality are refractory shock, uncontrollable alterations of coagulation, and multiorgan failure. Some authors have proposed the early use of plasmafiltration and high flow hemodiafiltration for refractory septic shock. Most authors initiate treatment with a short session of plasmafiltration followed by continuous hemodiafiltration. A 13-year-old girl presented refractory meningococcal septic shock, disseminated intravascular coagulation, and acute renal failure unresponsive to volume expansion and high doses of adrenalin and noradrenaline. She received simultaneous treatment with plasmafiltration and continuous venovenous hemodiafiltration for 30 hours. Two pumps of extrarenal purification placed in parallel through the same double line catheter were used. Fast hemodynamic stabilization and control of the coagulopathy were achieved. The patient survived with progressive recovery of renal function but required amputation of the inferior left limb. Continuous plasmafiltration and venovenous hemodiafiltration can be used simultaneously for the treatment of older children with septic shock, severe coagulopathy, and hypervolemia.