The Treasury is a pretty small, temple-shaped building, made of Parian marble, in contrast to the rest of the monuments of this period which were made of porous stone. Herodote states that the monument was famous in his times for the rich sculpture decoration, which is one of the best samples of the Archaic sculpture. On the façade, between the two antae, stood two korae, to support the architrave, instead of the usual columns; these sculptures are an excellent sample of the Ionic plastic art of the period. An Ionic-style kymation (a decorative motif imitating a wave) and a nice frieze decorate the architrave on all four sides of the building, depicting episodes of Greek mythology. On the eastern side it is presented the assembly of the gods at Olympus, who watch the siege of Troia; on the southern side it is depicted the rape of Leucippidae by Dioskouroi; the western side of the frieze presents the judgement of Paris and the northern one, the best preserved, depicts the Gigantomachy. The work is excellent: the powerful expression, the clear lines, the impressive figures and the care of details make this sculpture a masterpiece. The eastern pediment, at the main entrance of the monument, presents the conflict between Apollo and Hercules for the Delphic tripod; a theme pretty common in the art of Late Archaic period. The pediment is crowned by three acroteria: two Victories are depicted at the two ends and a Sphinx at the center.
Only the foundations of the monument and an astragal of the base are preserved today on site. The sculptural decoration survives in part and is housed at the Delphi Museum.