Sexually transmitted diseases are extremely prevalent among youth, and it is only by understanding the processes involved in negotiating sexual relationships that effective prevention and intervention programs can be designed. This study explores sexual communication among young adults, how gender and sexual orientation influence negotiation for safer sex, the strategies employed for risk reduction, and the barrier to safer sex. It assumes sexual behavior as a communicative form, both reflective and reflexive, subject to interpretation, and created interactively within and between sexual partners. Data from in-depth interviews with 30 undergraduates at the University of California, Berkeley were triangulated with questionnaires (n = 159), secondary sources and informal interviews with university officials. Participants were representative of arts and science students, ethnically diverse and of varying sexual orientations. Interviews focused on the normative influences of family, school and friends regarding sexuality; and how relationships and sex were negotiated. They investigated how strategies for risk reduction, attitudes about HIV and testing, and contraceptive practices were managed differently by gender and sexual orientation and what the barriers to safer sex were in various situations. Interviews focused on the normative influences of family, school and friends regarding sexuality; how relationships were negotiated, and how trust and risk were constructed within relationships; how strategies for risk reduction, attitudes about HIV and testing, and contraceptive practices were managed differently be gender and sexual orientation; and what the barriers were to safer sex. Friends, the social culture at university, and the interaction of the two with the developmental tasks characteristic of the period between adolescence and adulthood were more important influences than parents or high school sex education classes in how sexual relationships were managed. How and whether friends talked about sex and practiced safe sex were strong normative influences in predicting safer sex among individuals. Negotiating for safer sex contains elements of impression management, requires assertiveness and takes constant effort, even among those who have made the most progress in incorporating it. Practicing safer sex involves a complicated process of sexual negotiation, requiring a degree of open communication about sexual desire and intent that is not widely available in this culture, and still less among young people. Risk and thus how sex is negotiated is assessed differently by gender, and varies further according to the degree of intimacy in the relationship or the sex act being contemplated. How sex is negotiated depends on the construction of risk and trust which differ by the type of relationship or sexual encounter being contemplated.(ABSTRACT TRUNCATED AT 400 WORDS)