Almost entirely built in sandstone, it is considered one of the most important examples of Sardinian Romanesque architecture.
The basilica has a façade in undecorated sandstone, with three bays corresponding to the interior's nave and two aisles.
Near the pilasters flanking the portal are two old columns, leading to the hypothesis that the church once had a portico or similar structure.
More numerous are the features of the apse, with semi-columns supported by plinths and ending in leaf-shaped capitals, Lombard bands and six single-mullioned windows (the three lower ones lighting the church's crypt).
In the interior the aisles and the nave are divided by seven columns with arcades, made of material from ancient settlements of the area.