A study was carried out on 200 patients of ages 20-40 years suffering from acute viral hepatitis. Sera were tested for markers of hepatitis B (HBsAg, and IgM anti-HBc) and hepatitis A (IgM-anti-HAV) by the ELISA technique. Sera negative for the markers of both viruses: Hepatitis A (HAV) and Hepatitis B (HBV) were subsequently tested for IGM Heterophil antibodies against Epstein-Barr virus (EBV) by the Monospot slide test to diagnose acute infectious mononucleosis and tested for anti-CMV (IgM) by ELISA technique for the diagnosis of acute Cytomegalovirus (CMV) infection. Non-A, non-B hepatitis (NANB) was diagnosed by exclusion. The results of the study showed that 133 (66.5%) patients had evidence of HBV infection, while only 9(4.5%) were diagnosed as HAV infection. EBV and CMV were the possible etiological agents of acute viral hepatitis in (3.5%) and 1%) respectively. Accordingly the Non-A, non-B hepatitis in this study amounts to (24.5%) of the acute viral hepatitis.