From among 2,375 young men, examined by doctors, 111 tattooed subjects were found. Twenty one subjects reported engaging in promiscuous sexual behavior or being intravenous drug abusers, and so were excluded. The other 90 were evaluated. To make up the control group, 180 non-tattooed subjects from the remaining 2,264, who neither engaged in promiscuous sexual activity nor were intravenous drug abusers, were matched from household registry reports by age, sex, education, occupation, and geographic origin from Mainland China, where their parents were born. IgG antibody of hepatitis A (anti-HAV) and markers of hepatitis B were tested in serum with radioimmunoassay. In the prevalence rate of hepatitis A and carrier rate of HBsAg there were no differences between the tattooed and the non-tattooed groups. However, the prevalence odds ratio of hepatitis B virus (HBV) infection for the tattooed group was 8.1 (95% CI 1.9-34.8) as compared to the non-tattooed groups. Moreover, there was a trend correlation when the prevalence rates of hepatitis B were compared for the group with multiple sites of tattoos, for the group with one site of tattoos, and for the non-tattooed group (p = 0.002). These findings suggested an association between HBV infection and tattooing. Tattoo exposure, with improper or no sterilization of the needle, seems to appear to increase the risk of HBV infection in the already high risk endemic area in question.