Four women aged 35 to 57 years (m: 49.2) with primary biliary cirrhosis and intractable pruritus had an estimated median survival time according to Christensen between 6 and 50 months (m: 27). They were enrolled in a therapeutic trial associating plasma exchange (PE) and immunosuppressive drugs. During the first 2 months, they received prednisone 15 mg/day, cyclophosphamide 2 mg/kg BW/day and 28 PE (60 ml/kg BW). Pruritus disappeared rapidly. After 2 months, mean levels of bilirubin, alkaline phosphatases, IgM and anti-mitochondrial antibodies dropped by 27 p. 100, 47 p. 100, 50 p. 100 and 85 p. 100 respectively, whereas amino-transferase and gamma-glutamyl-transpeptidase activities were unaltered. Two patients then received supportive therapy only: one was lost to follow-up after one year, the other died 50 months later from liver failure. The third patient received PE only when intractable pruritus reappeared: anti-mitochondrial antibodies, IgM and alkaline phosphatases remained below initial values for 38 months, until successful liver transplantation was performed. The fourth patient was treated on a long term basis by PE twice a month, prednisone 10 mg/day for 3 years and cyclophosphamide 1 mg/kgBW/day for one year only. Her initial estimated survival time was 6 months, but 3 years later she developed portal hypertension; anti-mitochondrial antibody titer was between 0 and 1/80, alkaline phosphatase levels reduced by 80 p. 100 to 70 p. 100; bilirubin level up by 50 p. 100. The mean survival time for the 4 patients exceeded 34 months, results better than those obtained with other kinds of therapy.