Acquired haemophilia A (AHA) is a rare bleeding disorder and the main cause of coagulation factor deficiency. AHA is caused by the development of antibodies, also known as inhibitors, against coagulation factor VIII (FVIII) that neutralize their activity which, in more serious forms, results in bleeding. This article describes a case of a 54-year-old woman with a diagnosis of Systemic Lupus Erythematosus (SLE) occurring for the past 12 years, who presented to the clinic because of multiple spontaneous ecchymoses. Clinical findings included prolonged thromboplastin time (aPTT), absence of factor VIII activity, high factor VIII inhibitor levels (208 BU/mL), and crossed PTT with no evidence of correction after serial dilutions. AHA was considered secondary to SLE, and due to the severity of the ecchymoses, the patient required Feiba VH®, methylprednisolone and cyclophosphamide therapy, although no adequate response was achieved. As a result, four doses of weekly rituximab therapy were given and coagulation profile standardization and complete clinical improvement were achieved.