Paroxysmal nocturnal hemoglobinuria (PNH) is an uncommon blood stem cell disorder. The acquired defect is in the cell membrane of the precursor of the affected clone, which renders erythrocytes, platelets and granulocytes unusually sensitive to the hemolytic effects of complement. It is characterized by chronic hemolysis, intermittent hemoglobinuria, thrombotic events and bone marrow hypoplasia. Hemolysis is precipitated by infection, strenuous exercise, surgery or menstruation. The dilemma of managing a PNH patient is that both the periodontal infection and the surgical treatment are precipitating factors. Management is further complicated by the fact that the patient is receiving corticosteroids. The treatment of the PNH patient is complex and potentially hazardous. It requires close cooperation between the periodontist and the hematologist. This paper describes the management of one such case.