Authenticity is seen by many as a key for good learning and education. There is talk of authentic instruction, authentic learning, authentic problems, authentic assessment, authentic tools and authentic teachers. The problem is that while authenticity is an often-used adjective describing almost all aspects of teaching and learning, the concept itself is not very well researched. This qualitative study examines--based on data collected via interviews and focus groups--which criteria students in secondary education use when determining if their teachers are authentic. It yielded four criteria learners use: Expertise, Passion, Unicity and Distance.