One of the major advances in the management of patients on regular dialysis has been the control of the spread of hepatitis B virus (HBV) infection in dialysis units. The rate of HBsAg positive patients on regular dialysis in the developed world is currently low, but outbreaks of HBV continue to occur. The diffusion of HBV in dialysis units in developing countries is higher, although available information is not abundant. There are limited data on the natural history of HBV in the dialysis population; they support a detrimental effect of HBV on survival in dialysis patients. The HBV viral load in HbsAg-positive dialysis patients appears low and stable over time and numerous mechanisms have been posited to explain it. Several assays for detecting HBV DNA in serum are available but they should not be used for purposes of routine screening within dialysis units. The epidemiology and clinical significance of occult HBV infection in the dialysis population needs to be addressed adequately - this remains an area of active research. Recent recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No controlled trials for the treatment of hepatitis B with either interferon or lamivudine in dialysis patients are currently available.