Liver cancer is a major global health problem and hepatocellular carcinoma (HCC) accounts for 75% of all liver carcinoma. HCC occurs more often in men than in women and mostly in people 50 to 60 years old. The disease is more common in parts of sub-Saharan Africa and Asia than in North and South America and Europe. Nevertheless its incidence increased over the past 4 decades in some Western countries. Worldwide, liver carcinoma is the 5th most common cancer and 3rd most common cause of cancer mortality (behind only lung and colorectal cancer) with approximately 680,000 annual deaths. Unlike most of the other malignancies, HCC almost entirely develops in the context of inflammation and organ injury and is related to cirrhosis in about 85% of the cases. Among underlying etiologies of liver cirrhosis, most frequent are viral infection and toxic substances, mostly alcohol. The main HCC risk factor in Eastern Asia and Africa is hepatitis B virus infection. Hepatitis C virus infection is the main risk factor in Western countries. Hereditary hemochromatosis is not a very frequent cause of liver cirrhosis, but these patients are at higher risk for HCC compared with other etiologies of cirrhosis. Aflatoxins, cancer-causing substances made by a type of plant mold, can play a role in some countries in Asia and Africa, and can have a synergistic effect with hepatitis B infection.