A 36-year-old woman developed postpartum haemorrhage after an uncomplicated vaginal delivery, followed by disseminated intravascular coagulation, thrombotic microangiopathy, and persistent anuric kidney failure. Contrast-enhanced computed tomography showed bilateral reversal of corticomedullary enhancement, consistent with renal cortical necrosis. Despite kidney replacement therapy and 13 litres of ultrafiltration, she remained oxygen-dependent, prompting cardiac evaluation on postpartum day 11, which revealed severe left ventricular systolic dysfunction (ejection fraction 25%) consistent with peripartum cardiomyopathy. Cardiac function recovered with medical therapy, whereas kidney function remained irreversible, requiring dialysis and transplantation. Renal cortical necrosis and peripartum cardiomyopathy are linked to endothelial dysfunction, yet their coexistence has rarely been reported. Cardiac dysfunction emerged only after substantial fluid removal, arguing against volume overload alone and suggesting a shared postpartum endotheliopathy. Persistent oxygen requirement despite adequate decongestion should prompt early cardiac assessment rather than being attributed to fluid overload alone.