Abstract. – This article discusses in some detail the hypothesis proposed by Michael Dietrich concerning our understanding of rongorongo. Dietrich argues that rongorongo is not a script but a graphic system that contains the celestial knowledge of the prehistoric Oceanic peoples, developed and used for navigation. Dietrich’s methodology and conclusions are then compared with those proposed by Thomas Barthel and Steven Fischer as well as with the results of recent research. The implications of Dietrich’s hypothesis for Easter Island and Pacific studies and for scientific inquiry in general are discussed, with the purpose of inviting the scientific community to critically review our current knowledge on rongorongo. [Polynesia, Easter Island, rongorongo, Polynesian astronomy, navigation]