A patient with acute hepatic insufficiency induced by a drug presented to our institution, and we performed a novel plasmapheresis that we call plasma dia-filtration (PDF). The patient was a 36 year old woman. She underwent 11 sessions of PDF for a duration of about 9 h for each procedure using the Evacure EC-2A filter together with 20 units of fresh frozen plasma and dialysate simultaneously. Serum levels of total bilirubin and prothrombin time were significantly improved after she underwent each procedure. However, after the third procedure the levels returned to the same level as on the previous day. Encephalopathy improved after the first procedure, and this improvement was maintained until the ninth procedure. The patient prepared to undergo liver transplantation after the tenth procedure because of the development of hepatic coma, but she died of respiratory insufficiency before undergoing the procedure. Accordingly in this case, PDF worked to maintain liver function in acute liver failure and may act as bridge therapy until the patient can undergo liver transplantation.