Hepatocellular carcinoma(HCC) is the most common primary liver malignancy. The incidence of hepatocellular carcinoma has increased dramatically by 80% over the past two decades in the United States. Numerous basic science and clinical studies have documented a strong association between hepatocellular carcinoma and the metabolic syndrome. These studies have documented that, in most patients, non-alcoholic fatty liver disease is the hepatic manifestation of the metabolic syndrome, which may progress to hepatocellular carcinoma through the cirrhotic process. However, minority of patients with non-alcoholic fatty liver disease may progress to hepatocellular carcinoma without cirrhosis.This review summarizes the current literature of the link between hepatocellular carcinoma and metabolic syndrome with special emphasis on various components of the metabolic syndrome including risk of association with obesity, diabetes mellitus, hyperlipidemia,and hypertension. Current understanding of pathophysiology, clinical features, treatments, outcomes,and surveillance of hepatocellular carcinoma in the background of metabolic syndrome and non-alcoholic fatty liver disease is reviewed. With the current epidemic of metabolic syndrome, the number of patients with non-alcoholic fatty liver disease is increasing.Subsequently, it is expected that the incidence and prevalence of HCC will also increase. It is very important for the scientific community to shed more light on the pathogenesis of HCC with metabolic syndrome,both with and without cirrhosis. At the same time it is also important to quantify the risk of hepatocellular carcinoma associated with the metabolic syndrome in a prospective setting and develop surveillance recommendations for detection of hepatocellular carcinoma in patients with metabolic syndrome. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. The incidence of hepatocellular carcinoma has dramatically increased by 80% over the past two decades in the United States. Numerous basic science and clinical studies have documented a strong association between hepatocellular carcinoma and the metabolic syndrome. These studies have documented that, in most patients, non-alcoholic fatty liver disease is the hepatic manifestation of the metabolic syndrome, which may progress to hepatocellular carcinoma through the cirrhotic process. However, minority of patients with non-alcoholic fatty liver disease may progress to hepatocellular carcinoma without cirrhosis. this review summarizes the current literature of the link between hepatocellular carcinoma and metabolic syndrome with special emphasis on various components of the metabolic syndrome including risk of association with obesity, diabetes mellitus, hyperlipidemia, and hypertension. Current understanding of path ophysiology, clinical features, treatments, outcomes, and surveillance of hepatocellular carcinoma in the background of metabolic syndrome and non-alcoholic fatty liver disease is reviewed. With the current epidemic of metabolic syndrome, the number of patients with non-alcoholic fatty liver disease is increasing.Subsequently, it is very important for the scientific community to shed more light on the pathogenesis of HCC with metabolic syndrome, both with and without cirrhosis. At the same time it is also important to quantify the risk of hepatocellular carcinoma associated with the metabolic syndrome in a prospective setting and develop surveillance recommendations for detection of hepatocellular carcinoma in patients with metabolic syndrome.