Hepatocellular carcinoma represents a leading cause of death in different parts of the world. Many risk factors play an important role in the development of HCC, most of which is hepatitis B and C, and exposure to carcinogens e.g. aflatoxin. Glutathione S transferase enzyme is an enzyme that helps in detoxifying carcinogens. Studying the genes of GST especially GSTM1 and GSTT1 may help in setting a relationship between mutations in the genes and development of HCC.