Its facade is the most beautiful part of this church, which was financed in the 13th century by two prominent Palermo dynasties, the Chiaromonte and Sclafani families. Both the lava-mosaic-enclosed main portal and the distinctive rose window are in the Norman architectural style.

In contrast to the classic medieval front is the interior, which was reconstructed with baroque adornment centuries later. Here you'll see the last stuccoes of followers of the Serpotta School, completed between 1711 and 1729. You can still see Serpotta's mark, a serpe (Sicilian for snake). The medieval cloister was originally built in the Catalan-Gothic style, surrounding a central fountain. Lying at a corner of the cloister, the chapter house preserves many of its original 13th-century architectural features. Embedded in the wall of the stairs leading from the church's side entrance is an ancient Roman tomb. Sant'Agostino lies adjacent to Mercato di Capo, the city's largest outdoor market.