Primary liver cancer is the sixth most common cancer in the world and the third cause of cancer-related death.Hepatocellular carcinoma(HCC)represents more than90%of primary liver cancers and generally occurs in patients with underlying chronic liver disease such as viral hepatitis,hemochromatosis,primary biliary cirrhosis and non-alcoholic steatohepatitis.Especially cirrhotic patients are at risk of HCC and regular surveillance could enable early detection and therapy,with potentially improved outcome.We here summarize existing evidence for surveillance including ultrasound,other radiological modalities and various serum biomarkers,and current international guideline recommendations for surveillance.Ultrasound andα-fetoprotein(alone or in combination)are most frequently used for surveillance,but their sensitivities and specificities are still far from perfect,and evidence for surveillance remains weak and controversial.Various other potential surveillance tools have been tested,including serum markers as des-carboxyprothrombin,lectin-boundα-fetoprotein,and(most recently)circulating TIE2-expressing monocytes,and radiological investigations such as computed tomographyscan or magnetic resonance imaging-scan.Although early results appear promising,these tools have generally been tested in diagnostic rather than surveillance setting,and in most cases,no detailed information is available on their cost-effectiveness.For the near future,it remains important to define those patients with highest risk of HCC and most benefit from surveillance,and to restrict surveillance to these categories. Primary liver cancer is the sixth most common cancer in the world and the third cause of cancer-related death. Hepatatocellular carcinoma (HCC) represents more than 90% of primary liver cancers and generally occurs in patients with underlying chronic liver disease such as viral hepatitis, hemochromatosis, primary biliary cirrhosis and non-alcoholic steatohepatitis. Especially cirrhotic patients are at risk of HCC and regular surveillance could enable early detection and therapy, with potentially improved outcome. We summarize existing evidence for surveillance including ultrasound, other radiological modalities and various serums biomarkers, and current international guideline recommendations for surveillance. Ultrasound and alpha-fetoprotein (alone or in combination) are most frequently used for surveillance, but their sensitivities and specificities are still far from perfect, and evidence for for surveillance remains weak and controversial. Verious other potential surveillance tools have been tested, includ ing serum markers as des-carboxyprothrombin, lectin-bound α-fetoprotein, and (most recently) circulating TIE2-expressing monocytes, and radiological investigations such as computed tomographs or magnetic resonance imaging-scan. Although early results appear promising, these tools have generally been tested in diagnostic rather than surveillance setting, and in most cases, no detailed information is available on their cost-effectiveness. For the near future, it remains important to define those patients with highest risk of HCC and most benefit from surveillance, and to restrict surveillance to these categories.