Antibody profiles for cytomegalovirus (CMV), hepatitis A virus (HAV), hepatitis B virus (HBV) and the delta-agent were determined on 55 serum samples drawn from 55 Saudi patients on maintenance haemodialysis for periods ranging from 1.5 months to 2 years. The exposure rates for CMV, HAV, and HBV were 100%, 100%, and 72.7%, respectively. There was no intersex difference in positivity for HBV surface antigen (HBsAg), antibody to HBsAg (anti-HBs), antibody to HBV core antigen (anti-HBc); 15.4%, 65.4%, 3.8% in males and 6.9%, 55.2%, and 0% in females, respectively. Among six HBsAg carriers, one and three were positive for e antigen (HBeAg) and antibody to HBeAg (anti-HBe), respectively, with two negative for HBeAg and anti-HBe. The six carriers were also negative for anti-delta antibody. A comparison of the above antibody profile to the profile of voluntary blood donors and those seeking treatment for minor ailments in the local general hospital, obtained earlier using identical test procedures, revealed no difference for CMV and HAV exposure rate. The HBV exposure rate was higher in the haemodialysed patients (P less than 0.001). The epidemiological measures for preventing nosocomial viral hepatitis including immunisation of susceptibles, can be supplemented, among carriers, by interferon and acyclovir therapy for active viral replication. In HBV hyperendemic areas, haemodialysis patients exposed to HBV should be screened periodically for early signs of hepatocellular carcinoma.