Renal disease is very common in patients with systemic lupus erythematosis (SLE) and it may emerge during pregnancy or the post-partum period. Patients with anti-phospholipid syndrome (APS)are also at risk of renal disease. We present a case of acute renal failure in the post-partum period in a patient with SLE and APS. This case illustrates the potential difficulties in reaching a diagnosis in such a patient. It also illustrates the complexities of management and the potential interactions between SLE, Haemolysis, elevated liver enzymes and low platelets syndrome, thrombotic thrombocytopenic purpura, haemolytic uraemic syndrome and APS. We also review the role of plasma exchange therapy in managing our patient.