Since Haissaguerre and his colleagues demonstrated the importance of the pulmonary veins in the generation of atrial fibrillation (AF) in 1998, a variety of different ablative interventions have been performed to eliminate AF. Various complications related to catheterization, ablation itself including pulmonary vein stenosis, pericardial effusion, stroke, and atrioesophageal fistula have been reported. Disseminated intravascular coagulation (DIC) is a systemic syndrome characterized by enhanced activation of coagulation with some intravascular fibrin formation and deposition. This is the first report, to our knowledge, of a patient whose condition was complicated by DIC after segmental ostial isolation of pulmonary veins for persistent AF. The patient has completely recovered from the DIC by hemodialysis, administration of blood constituents for 15 days.