The objective of this study was to understand the ethical and professional ethics representations present in the discourse of librarians who work in enterprises in the state of Santa Catarina. Firstly, the main concepts of ethics and its contemporary approaches, the deontological ethics and the librarians’ ethics, and the business environment and its ethical challenges are discussed. The theoretical and methodological substantiations focused on the concepts of the sociology of knowledge, social constructivism, and the social representations theory. The data for this qualitative research was obtained through a semi-structured interview and was analyzed based on the “Discourse of the Collective Subject” (DCS). It was possible to identify in the discourse of the professionals: the lack of knowledge regarding ethical concepts and professional ethics and its importance, as well as the lack of familiarity with the Professional Code of Ethics of the Brazilian Librarians. Besides, the concepts of ethics and morality and their differences do not seem to be very clear to the interviewed librarians. Their notions of ethics are often related to otherness, character and behavior. There is a lack of understanding regarding the concept of professional ethics, which is reinforced by the non-familiarity with the contents of the Ethic Code of the Brazilian Librarians. Business ethical assumptions also have an influence on the ethical conduct of the librarian. It seems to be clear that there is no room for questioning the firm’s values, since the business ethical conduct prevails. Information dissemination is regulated in order to promote competitiveness and profitability for the enterprise. This research had as its background the post-modern context, in which values of technical and instrumental rationality are emphasized in thoughts and in the homus economicus’ actions, creating an ethical emptiness, that is, a lack of references and examples to guide human actions.