There are several reports describing acute liver decompensation in chronic carriers of HBsAg after withdrawal of chemotherapy or immunosuppressive therapy; recently the same was also reported for chronic HCV-RNA carriers. We retrospectively evaluated hepatic toxicity in eleven patients (6 carriers of HCV-RNA and 5 of HBsAg) autotransplanted at our Institution between March '92 and June '98. Male/female ratio was 7/4, median age 41 years (26-56). Nine patients (4 HBsAg) were affected by non-Hodgkin's lymphoma, 1 (HCV-RNA) by chronic myelogenous leukaemia and 1 (HBsAg) by breast cancer. In the immediate post-transplant period in only 1 patient (HBsAg carrier and affected by breast cancer) was hepatitis documented (at about 1 month from transplant) with an elevation of transaminase levels (x20-40 n.v.). Neither other complications, nor toxic deaths were observed. During the post-transplant follow-up (median 31 months, range 9-83) no hepatic abnormalities were observed. All patients are alive at 56 months (20-122) from diagnosis. Currently 10/11 patients are in complete remission, while 1 patient, affected by follicular centre lymphoma, is alive with disease 52 months from autologous stem cell transplantation. Our study shows that both conventional therapy and high-dose chemotherapy can be performed safely in chronic hepatitis B and C virus carriers.