The so called “Ninnion tablet” [National Museum of Athens 11036] is a votive red-figured attic clay plaque, found in the Sanctuary of Eleusis in 1895, and dated to ca. 370 BC. It is a private offering, not of the utmost artistic quality, with an original and so far unique subject of mortals encountering the Eleusinian deities. The complex iconography has been extensively discussed in classical scholarship. The main scene is crowned by a frieze depicting a series of lunar discs and crescents, in a variety of positions, which however has not been given much attention yet. In the present paper we will examine whether these moons might have an astronomical significance.