The purpose of this study was to examine gender differences in knowledge about HIV, the reported incidence of risky sexual behavior, and comfort with safer sexual practices among young adults. The conceptual framework was social role theory, which argues for the influence of gender roles on beliefs and social behaviors. Participants were 141 female and 131 male college students who responded to questions regarding their knowledge of HIV, risk-taking behaviors with respect to HIV, and comfort with safer sexual behaviors. Overall, respondents had accurate knowledge about HIV. However, men reported engaging in significantly more risky behaviors than women. More men reported that intercourse without a condom occurred in unplanned, spontaneous situations, while under the influence of alcohol or drugs, or with a person not well known. More women reported that intercourse without a condom occurred in long-term relationships. Women were significantly more comfortable abstaining from sexual intercourse and asking partners about their sexual history while men were significantly more comfortable buying condoms. Both men and women reported comfort using condoms. Gender roles help to explain why men are willing to take more risks, and in what situations risk taking is apt to occur. ©1995 John Wiley & Sons, Inc.