The Municipality of Pirri is located north of the city center of Cagliari and more precisely north-east of the Saint Michele hill. The historic town occupies a hollow that from the Monte Claro park in the south-west reaches the riu Saliu in the north-east. A hilly stretch opens from the foot of its historic center to the north-west border, delimited by the SS 554 and called Colle di Barracca Manna, the outskirts of the town itself and the highest point.

The area is mainly urbanized for almost all of its extension. In the Terramaini district, an homonymous green park was created, as a result of an urban redevelopment, covering an area of ​​eight hectares and adjacent to the Terramaini canal, with a mirror of stagnant water inside the basin of the nearby Molentargius pond.