The subject of the frieze is the procession of the Great Panathenaea, with the newly-made peplos of the goddess Athena being brought up to the Parthenon. The procession divides into two groups that start off from the south-west corner of the temple and meet again in the middle of the east front, at the scene with the peplos. Along the west front there are riders beside their mounts. At the north-west corner the procession is starting off, to be seen in full swing along the long sides of the cella. Figures of horsemen, chariot-racers, and apobatai appear. We also see men leading sacrificial oxen. And there are other figures, carrying baskets, waterjugs, and branches: these are the kanephoroi, hydrophoroi and thallophoroi respectively. On the east front, the peplos is being presented to the archon basileus: this scene is framed by the Olympian gods, in two separate groups.

There has been much speculation about all this: the interpolation of preparation scenes throughout the length of the two processions; the differences in the way the people taking part are dressed; and the presence of a disproportionately large number of riders and gods round the central peplos scene. And the plot thickens when we read the variations in the description of the procession by the ancient sources. Some scholars think that the procession was portrayed at different periods of time in Athenian history. Others see traces of an attempt to heroify those who fell at the battle of Marathon. The commonest view, however, is that the frieze was a gallimaufry of scenes from different times and places; that it was to be identified with an idealized representation of the facts of religion; and that it expressed the glory of the Athenian state and its protector deity Athena.