A continuing fundamental trend in the area of quality assurance in analytical laboratories are measures that enable trace-ability of analytical results to internationally renowned units, like e.g. the mole. Especially certified reference materials (CRMs) are important tools for achieving this goal. What are CRMs? Why do we need them in the field of mycotoxin analysis? Which kind of CRMs are currently available for the determination of mycotoxins and how should they be used? These are questions, which are increasingly being asked. This article attempts to answer these questions.