Plagiarism is unethical behaviour that can have negative consequences on the development of science and society. It also ruins the reputation of individuals and institutions. Plagiarism can be intended or unintended. The paper will focus on unintended plagiarism that is a result of absence of that topic in the education curricula. Teaching about plagiarism is part of so-called ethical literacy that is a subcategory of information literacy. A survey was conducted with the aim of finding out about the degree of knowledge about plagiarism among the students of Library and Information Science at the Faculty of Humanities and Social Sciences, University of Zagreb. The analysis is based on an anonymous web questionnaire with 20 questions. The presumption is that the students do not know enough about plagiarism, they have not had any experiences with plagiarism during their education and they do not know what self- plagiarism is. Another presumption is that the students get detailed instructions about how to cite sources, but do not know enough about the concept of authorship. The conclusion will be made about the inclusion of this segment of information literacy in education curricula. New surveys will be proposed (on local and national level).