The aim of this study to report data is derived from an investigation of the knowledge, attitudes, beliefs and practices of AIDS prevention among the large the descendant of the Iranian prisoners. Using a multistage area sampling method, a random sample of individuals aged 18-65 years in southern coastwise of the Caspian Sea from February to December 2006. To select a representative sample of the prisoners' population within 5 different prisons in Mazandaran Province had the same probability to be sampled. Prisoners who agreed to participate were given a four-page self-administered questionnaire. 760 (88%) of the 2000 eligible participants completed the questionnaire. The mean age of respondents was 30.05 +/- 8.1 years ranging from 18 to 59, 1686 (95.8%) were male and mostly married 1054 (59.9%) and had received secondary education or above 1178 (66.9%). Most respondents (1690, 96%) had household income levels low or average and 716 (40.7%) were out of work. The findings indicated that the respondents had average to fairly good knowledge about AIDS. The correct answers ranged from 11.9% to about 85.9%. Also the results showed that the majority of the respondents were strongly agree or agree with the statement that people with AIDS should have social right to study or work (1378, 78.3%) or with the statement that AIDS is public health problem (1522, 86.5%). The majority of the respondents (1538, 83.4%) said that the mass media including radio, television and newspapers were the main source of their information about HIV/AIDS. Such findings suggest that prevention programs should be encourage and these might have the potential role to limit the emergence of Iran's HIV/AIDS epidemic especially in prison's this of country.