Background: Because of high-risk behaviours, sedentary lifestyle and side effects of medications, psychiatric patients are at risk of viral hepatitis, alcohol-related liver disease and non-alcoholic fatty liver disease. We aimed to study the incidence of hepatocellular carcinoma (HCC) and cirrhotic complications in psychiatric patients. Methods: We identified consecutive adult patients in all public hospitals and clinics in Hong Kong with psychiatric diagnoses between year 2003 and 2007 using the Clinical Data Analysis and Reporting System, which represents inpatient and outpatient data of approximately 80% of the 7.4-million local population. The patients were followed for liver-related events (HCC and cirrhotic complications) and deaths until December 2017. Age-and sex-standardized incidence ratio (SIR) of HCC in psychiatric patients to the general population was estimated by Poisson model. Results: We included 105,763 psychiatric patients without prior liver-related events in the final analysis. During a median (interquartile range) follow-up of 12.4 (11.0-13.7) years, 1461 (1.4%) patients developed liver-related events; 472 (0.4%) patients developed HCC. Compared with the general population, psychiatric patients had increased incidence of HCC (SIR 1.42, 95% confidence interval [CI] 1.28-1.57, P < 0.001). The SIR was highest in patients with drug-induced (SIR 3.18, 95% CI 2.41-4.11, P < 0.001) and alcohol-induced mental disorders (SIR 2.98, 95% CI 2.30-3.81, P < 0.001), but was also increased in patients with psychotic disorders (SIR 1.39, 95% CI 1.16-1.65, P < 0.001) and mood disorders (SIR 1.16, 95% CI 1.00-1.34, P = 0.047). Liver disease was the fifth most common cause of death in this population, accounting for 595 of 10,614 (5.6%) deaths. Importantly, 569 (38.9%) patients were not known to have liver diseases at the time of liver-related events. The median age at HCC diagnosis (61 [range 26-83] years) was older and the median overall survival (8.0 [95% CI 5.0-10.9] months) after HCC diagnosis was shorter in this cohort of psychiatric patients than other reports from Hong Kong.