The outer wall of Petavius is unusually wide in proportion to the diameter, and displays a double rim along the south and west sides.

The convex crater floor has been resurfaced by lava flow, and displays a rille system named the Rimae Petavius.

The large central mountains are a prominent formation with multiple peaks, climbing 1.7 kilometers above the floor.

It is thought that this may have been created by radial outbursts during the original impact that swept the area clean.

[2] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Petavius.