Paroxysmal nocturnal haemoglobinuria (PNH, Strübing–Marchiafava–Micheli syndrome) is a rare acquired clonal disorder of haematopoietic stem cells causing intravascular haemolysis, haemoglobinuria and occasionally severe venous thrombotic complications. The most important complications of PNH, are thrombotic events, especially affecting intra-abdominal veins. Hepatic vein thrombosis (Budd-Chiari syndrome) is common in PNH patients. Herein, we present a case who was admitted to our clinic with bicytopenia, splenomegaly and diagnosed to have PNH during hospitalization.