Posterior reversible encephalopathy syndrome is a sporadic disease commonly presenting as headache, vomiting, visual disturbances, seizures and confusion. Acute changes in blood pressure are commonly associated with this. 1 It is understood that many medical conditions and medicines raise the risk of posterior reversible encephalopathy syndrome. We report an unusual case of posterior reversible encephalopathy syndrome in patient with autoimmune haemolytic anaemia. Due to the advancement and affordability of brain imaging with magnetic resonance imaging (MRI), identification of posterior reversible encephalopathy syndrome (PRES) is possible. A high index of suspicion and prompt treatment can decrease the morbidity, decrease mortality and result in an early recovery. Haemolysis is the premature destruction of erythrocytes. Haemolysis expedites to haemolytic anaemia when the increased loss of red blood cells cannot be replaced by bone marrow activity. Immune haemolysis is a shortening of the survival of red blood cells due to antibodies, either directly or indirectly. Autoantibodies or alloantibodies can be such antibodies. In order to choose suitable blood for transfusion, these atypical antibodies have to be detected in the patient's serum.