The near-destroyed pyramid of Pepi I once measured about 78.75 metres to a side. With a slope of 53°07'48" it had a height of presumably 52.5 metres. These measurements are conform with the standards for the royal pyramids of the 6th Dynasty.
It is now reduced to a low mound of rubble, about 12 metres high. A large crater in the middle has been dug by stone robbers.
With the exception that in Pepi's pyramid, the Pyramid Texts cover more of the walls, its substructure is very similar to that of Teti. The pyramid is entered by an entrance, covered by an entrance chapel and located at ground-level in the centre of the north side of the pyramid. From there, a descending passage goes down into the rock to a horizontal corridor chamber.
A horizontal passage, once blocked by three portcullis slabs, continues towards the antechamber, to the west of which is located the king's burial chamber. In this burial chamber, a pink granite canopic chest was found, sunk into the floor in front of the sarcophagus and nearby a tightly packed bundle of viscera, assumed to have been Pepi I's. The sarcophagus itself was found empty. It was made of a hard, dark stone and inscribed with a line from the Pyramid Texts.
To the east of the antechamber is located a small chamber with three niches or magazines.
Except for the 3 niches, most of this pyramid's substructure was 'decorated'. The walls around the sarcophagus in the burial chamber were decorated with the reed-mat booth, as was found in Unas' pyramid as well. Most of the other walls are covered with vertical columns of hieroglyphs, painted green, the colour of re-birth. This was the first -but not the oldest- pyramid to have been found inscribed with a collection of religious texts, spells etc. known today as Pyramid Texts.