Objectives/Hypothesis: Chronic hepatitis B virus infection is a significant worldwide health problem. It affects 350 to 400 million people. The patients with chronic hepatitis B virus infection have a significant risk for the development of cirrhosis or hepatocellular carcinoma. Full awareness of the mechanisms of transmission can allows susceptible individuals to refrain from this infection. Cerumen has never been studied as a route for hepatitis B transmission. The. of the study was evaluate the importance of cerumen in transmission of hepatitis B virus infection. Study Design: This study was performed on forty patients with confirmed hepatitis B virus infection. Methods: Forty cerumen specimens collected from the patients with hepatitis B virus DNA in their sera were prospectively analyzed for the presence of hepatitis B virus DNA by real-time polymerase chain reaction. Results: Eleven of 40 cerumen specimens (27.5%) were positive for hepatitis B virus DNA, with counts ranging from 4.2 x 10(2) to 4.7 x 10(6) copies per sample. There was positive correlation between hepatitis B virus DNA concentrations of serum and cerumen. Half of hepatitis B e antigen (HBeAg)-positive patients had detectable hepatitis B virus DNA levels (5.7 x 10(2) to 4.7 x 10(6) copies) in cerumen specimens, whereas 12.5% of cerumen specimens from anti-HBe-positive patients had hepatitis B virus DNA levels (4.2 x 10(2) to 7.0 x 10(3) copies). Conclusion: Cerumen can be a potential source of transmission. Therefore, this route should be investigated in further studies for horizontal, nosocomial, and occupational transmission of hepatitis B.