It has been reported that the presence of anti-nuclear antibody against a 210kDa glycoprotein of nuclear pore complex (anti-gp210) is highly speciﬁc for primary biliary cirrhosis (PBC). The aim of the present study was to investigate the signiﬁcance of anti-gp210, especially as a prognostic marker. The presence of anti-gp210 was ascertained in 113 patients with PBC and 162 controls by indirect immunoﬂuorescence assay using HepG2 cells and immunoblotting analysis using nuclear extracts from HeLa cells. Anti-gp210 was detected in 25 of the 113 (22.1%) patients. None of the 162 controls was positive for anti-gp210. The appearance and titre of anti-gp210 in the patients with PBC did not vary from the time of diagnosis and through their clinical course. Anti-mitochondrial antibodies (AMA), including antibodies against pyruvate dehydrogenase complex, branched chain α-ketoacid dehydrogenase complex and α-ketoglutarate dehydrogenase complex, were not detected by enzyme-linked immunosorbent assay in ﬁve of the 113 (4.4%) patients with PBC. However, anti-gp210 alone was positive in one of these ﬁve patients. The difference in prognosis was statistically signiﬁcant; patients with PBC positive for anti-gp210 died from hepatic failure more frequently than those who were negative (P < 0.01), although there were no statistically signiﬁcant differences in the frequency of jaundice and the histological stage at the time of diagnosis between the two groups. We suggest that the presence of anti-gp210 is one of the independent prognostic markers able to predict, at the time of diagnosis, a poor outcome in patients with PBC.