Inmates from three Mexican prison sites were surveyed as to their knowledge of AIDS and AIDS transmission. The majority of the inmates sampled were aware of the primary means of transmission--male homosexual sex and illegal intravenous (IV) drug use. There are low levels of IV drug users and male homosexuals and bisexuals in the prisons surveyed. Low levels of homosexual conduct may be attributed to Mexico's universal practice of allowing conjugal visits, and Mexico therefore may not have to concern itself with the spread of AIDS behind prison walls as is the case in the United States. However, Mexico may need to concern itself with testing prostitutes who ply their trade in Mexican prisons. Tables, endnotes, references