Antineoplaston AS2-1 exhibits cytostatic growth inhibition of human hepatocellular carcinoma cells in vitro and showed minimum adverse effects in a phase I clinical trial. Liver cancer is difficult to control because of multicentricity and underlying liver disease. We reviewed two clinical cases of liver cancer (hepatocellular carcinoma and multiple liver metastases from colon cancer) in whom we believe antineoplaston A2-1 was useful as a maintenance therapy after transcatheter arterial embolization (TAE) and microwave coagulation necrosis (MCN). The two patients have continued to be in good condition for more than two years without limitation of their normal activities. Antineoplaston AS2-1 may be effective and useful as a maintenance agent after TAE and MCN in patients with liver cancer.