Background and Aims: In other forms of chronic liver disease, measurement of portal pressure is of prognostic value, but this has not yet been established in primary biliary cholangitis (PBC). The aim of the study is to determine the prognostic value of hepatic venous pressure gradient (HVPG) in relation to liver-related survival outcomes, as well as to the development of hepatic decompensation, oesophageal varices and variceal bleeding. Methods: Baseline HVPG and liver biopsies were obtained in 86 patients followed for 10 years in a controlled trial of colchicine treatment, and subsequently in a long-term observational cohort study for a further 30 years. Results: There were 49 Hepatic deaths in addition to 10 Liver Transplants (Hepatic death/transplant; n = 59). Some of these were associated with a significant variceal bleed within 3 months of death or transplant (Portal hypertension-associated death or transplant; n = 19). There were 63 deaths from all causes. During follow-up, oesophageal varices developed in 26 patients, whilst 17 bled from varices and 32 developed hepatic decompensation over a median follow-up of 18.1 years (1.9–28.5). Baseline HVPG was highly predictive of all 6 clinical outcomes and contributed significant predictive information additional to that provided by Mayo score and Ludwig stage. Conclusion: Measurement of baseline portal pressure is of significant prognostic value in primary biliary cholangitis.