Information literacy (IL) education in secondary schools should adequately prepare students for research activities in higher education and guide them toward becoming informed and responsible citizens. The existing international IL frameworks and tests are only partially aligned with the IL curricula in Slovenia. Therefore, a new IL framework for secondary education, consisting of seven IL standards and twenty performance indicators, was proposed together with two new assessment instruments (e.g. a multiple choice test and a self-evaluation questionnaire). Two groups of students were tested, namely first-year secondary students and first-year university students. The latter, before taking any university IL courses, were found to be more successful in all subject areas of the test, which could inter alia indicate a positive influence of secondary education on IL. Both student groups were the weakest in information search, followed by information evaluation and knowledge of legal/ethical issues. Secondary school students were less aware of their deficient search skills. The item analysis emphasized the need to put more educational efforts and practical examples into the teaching of IL topics where both groups were found deficient.