On the basis of a representative survey carried out in 2007 of the Portuguese population aged between 18 and 65, this study investigates the impact of factors during the course of sexual life on risk-taking behavior and perceptions among 3055 heterosexual men and women. A number of sexual biography profiles were identified through cluster analysis of indicators related to the identity, number and sequence of partners throughout life. We discovered different profiles, from systematic occasional partnerships and use of paid sex, more frequent among men, to the single partner profile, which is more prevalent among women. By carrying out several linear regression analyses, we were able to evaluate the predictive impact of biographical factors on condom use and prevention behavior. Our results indicate that sexual biographies are more important in explaining the prevalence of condom use with different sexual partners. On the other hand, fear of infection and information on HIV transmission seem to influence the cognitive mobilization of prevention strategies and change of sexual behavior. However, condom use is still more dependent on sexual life pattern and interaction with sexual partners.