Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC) are the most common cholestatic disorders in adulthood requiring hepatic transplantation. Although they run similar courses, they may have different problems before and after transplantation. The aim of this study was to compare pre- and post-transplant complications and outcomes in these two similar but distinct patient groups. One hundred and seventeen adult patients underwent liver transplantation at our institution over a 6 year period, including 19 with PSC and 20 with PBC. Pre-transplant there were no significant differences in age, liver biochemistry, haematology or Child-Pugh scores between the two groups. The mean duration of disease before transplant was longer in PSC patients (11.7 vs 6.5 years; P < 0.05). The prevalence of septic cholangitis was greater in PSC (58 vs 5%; P < 0.01) as was the requirement for surgical or radiological interventional procedures, excluding cholecystectomy (53 vs 0%; P < 0.01). At transplantation, four patients with PSC had previously unrecognized cholangiocarcinoma. In the pre-transplant period these four patients had uncontrolled biliary sepsis at the time of transplant vs five of 15 PSC patients without cholangiocarcinoma. Postoperatively, PSC patients had a greater prevalence of intra-abdominal sepsis requiring surgical or radiological intervention (42 vs 5%; P < 0.05). In comparison, patients with PBC had a high prevalence of skeletal complications (30 vs 10%; P < 0.05) particularly avascular necrosis (15 vs 0%). The prevalence of chronic rejection was similar in both groups (15%). Overall survival was higher in PBC patients (85 vs 63%; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)