This study aimed to identify the main factors that influence the behavior of members of Generation Y on Facebook, with emphasis on the aspect of exhibition. The study was based on the theories of Generational Cohort and Social Networking Sites, as well as on the concepts of exhibition and privacy. Initially, a literature review and semi-structured interviews raised 49 relevant variables. Further, field data were collected through a questionnaire. The sample consisted of 473 individuals. The analysis used statistical techniques of Multivariate Factors Analyses followed by Linear Regressions. At the end, factors emerged: Adherence, Dependency, Egocentrism, Emotional Neediness, Fears, Repentance, Privacy, Popularity, Risk and Banalization; the first four of which proved capable of explaining 22,4 percent of the variation in the exposure degree of the respondents’ behavior. Finally, the study shows how the behavior of voluntary exposure of Generation Y on Facebook is determined based on aspects such as: degree of binding, affinity and emotional involvement of the users with the site; self-centered attitudes that reveal preferences by talking about itself; exhibition feelings seeking emotional support, and recognition of harm in using associated with the incapacity to abandonment. Thus, Generation Y shows a intensive, voluntary, affective and notion of rewarding use of the site. And the users which more expose themselves exhibit behaviors of routine use, with access by different channels and different places in search of the benefits of sharing, showing an option for exposing himself. This option is on one hand conscious and on the other hand may become inevitable.