OBJECTIVES: To determine whether there is association between skin tattoos, Hepatitis-B and prisons, to investigate risk behaviors for Hepatitis-B and to describe characteristics of person who have tattoos. METHODS: This retrospective study consisted of a self-administered survey, and an ELISA blood test for viral hepatitis B. The study sample consisted of all 1/2001 privates at Adisorn Fort Hospital Saraburi who had tattoos (n1=46) and simple random sampling of another group of 46 volunteer privates who did not have tattoos. RESULTS: All privates (N=92) were male, age 22.88 b 1.41 years, 67 (72.8%) had graduated from elementary and high school, 29 were positive for Hepatitis-B antibodies (31.5%), 41 (44.6%) had sex with prostitutes, 3 (3.3%) did not use condom, 4 (4.3%) shared razors, 1 (1.1%) shared needles, 25 (27.2%) had been in jail, 87 (94.6%) drank alcohol, 43 (46.7%) had used amphetamines. Twenty (28.6%) had tattoos on 2 arms. Ten (14.3%) had tattoo on their back, 9 (19.6%) obtained their tattoos while in prison, 15 (32.6%) had a tattoo that was greater than 20% of the body's surface area. There was an association between skin tattoo and Hepatitis B (Chi Square, p<.01, OR: 15:9, 95%CI: 1.97-128.16), and an association between skin tattoo and having been in prison (Chi Square, p<.01, OR: 6.3, 95%CI: 2.1-18.8), There was no association between having been in jail and Hepatitis-B. Logistic regression was employed to find factors for Hepatitis-B. The variables that were associated with Hepatitis-B (<.05) were entered procedure to identify association with Hepatitis-B. Hit rate was 87.9, Pseudo R Square 0.464, Skin tattoos, a history of a family member with Hepatitis-B, and sharing needles increased the chance of getting Hepatitis-B. CONCLUSION: There were associations between jails and tattoos and viral hepatitis-B. Hygiene in tattoo' shops should be controlled by the government.