Ultrasound surveillance for hepatocellular carcinoma (HCC) may improve early tumour detection but may additionally result in surveillance-related harm through increased evaluation of non-HCC lesions. The incidence of these outcomes has not been reported outside North America. We aimed to report the outcomes of HCC surveillance with respect to both surveillance-related benefits and harms. We reviewed all HCC surveillance ultrasounds at a large Victorian tertiary hospital network in 2017 and followed their outcomes until 2021. Surveillance-related benefits were defined as early-stage HCC detection. Surveillance-related harm was defined as contrast imaging, biopsies or surgery performed to evaluate non-HCC liver lesions or false-positive alpha-fetoprotein levels. Five hundred and fifty-three patients were included (mean age 54.5 ± 12.3 years, males 67.5%, cirrhosis 50.3%). The most common liver disease aetiology was hepatitis B (53.9%). Over a median of 4.7 years follow-up, early-stage HCC was detected in 3.3% (5.4% in cirrhotic vs 1.1% in non-cirrhotic patients, P < 0.01). 75% of all HCCs were early-stage. Surveillance-related harm occurred in 12.5% (15.5% in cirrhotic vs 9.5% in non-cirrhotic patients, P < 0.04), although most harm was mild (12.1%). In subgroup analysis, the detection of early-stage HCC ranged between 0% (screened outside of guideline criteria and alcoholic cirrhotic patients) and 7.2% (hepatitis C cirrhosis). Harm occurred between 9% (non-cirrhotic hepatitis B) and 20.8% (thrombocytopenia). In our study, HCC surveillance was associated with early tumour detection, although many patients experienced mild surveillance-related harm. Novel surveillance strategies and pathways are required to improve detection in high-risk patients and minimise harm in low-risk patients.