Previous studies have shown that Hispanics know less about acquired immunodeficiency syndrome (AIDS) than non-Hispanics, but few studies have examined the role of language or socioeconomic status. We used data from a 1998 population-based sample survey of New Jersey adults to compare levels of AIDS knowledge among English and Spanish speakers, taking into account educational attainment and ability to speak English. Spanish speakers, especially those who filled out the questionnaire in Spanish, knew less about AIDS transmission, although their general AIDS knowledge was comparable to English speakers with similar educational attainment. Differences between Hispanics who speak primarily English and those who speak primarily Spanish underscore the idea that linguistic and cultural barriers vary within a cultural group and should be taken into account in the design of AIDS education programs.