We report a case of paroxysmal nocturnal hemoglobinuria (PNH) and review the literature regarding transfusion of red blood cells in PNH patients. A 42-year-old woman with myelodysplastic syndrome (MDS) complaining of right hypochondralgia and high fever was admitted to the hospital for acute cholecystitis with gall stone. Blood examination revealed bicytopenia (leukocytes, 1,700/microliters and hemoglobin, 8.5 g/dl) and bone marrow examination showed normocellular but hypererythroid bone marrow and dyshematopoiesis, which suggested MDS. Laboratory data revealed obstructive jaundice and hemolytic anemia. Positive sucrose and Ham tests, which were compatible with the diagnosis of PNH. Cholecystectomy was successful, and the patient showed no postoperative complications of increased hemolysis or thrombosis. As hemoglobin level gradually decreased for the first two postoperative weeks, filtrated white cell-depleted red blood cells (total, 1,000 ml) were transfused instead of washed red blood cells. No side effects of the transfusion were noted. On the basis of findings in this case and those reported in the literature, it is concluded that in some case of PNH, the use of washed red blood cells is unnecessary, and that the use of white cell-depleted red blood cells is indicated.