Introduction: Acquired haemophilia (AH) is a rare, acquired bleeding disorder with prevalence of 1: 1,000,000/year, due to autoantibodies against mainly Factor VIII which disrupt the coagulation cascade and cause potential life-threatening bleeding. Case Presentation : We report two patients with AH who had serious bleeding manifestations with differing outcomes: A lady with spontaneous bruising over her neck and face; A man with left upper arm haematoma post-fall. Upon admission, they had anaemia (Hb 11.2; 4.9 respectively), no thrombocytopenia but significant prolonged aPTT with normal PT/INR. Mixing study was uncorrected and showed time-dependent inhibition. Bethesda assay revealed significant reduced FVIII activity (<1%), normal FIX activity and presence of FVIII inhibitor (20 BU; 54.4 BU respectively). Fibrinogen level was normal. They were given immunosuppression with corticosteroids and cyclophosphamide for inhibitor elimination. They developed significant bleeding during hospitalisation requiring bypassing agents. The lady was discharged well with outpatient follow-up, whilst the man was transferred to haematology centre for further management. Conclusion : AH is an under-recognised haematological emergency. Clinicians require a high index of suspicion when facing a bleeding patient with isolated prolonged aPTT. Early recognition, prompt diagnosis and timely intervention will often avert a potentially disastrous outcome.