The cathedral stands in the historical town centre of Bosa, between the Corso Vittorio Emanuele II and the River Temo, at the height of the 19th-century bridge.
Externally the building is characterized by two cupolas covered in tiles of coloured majolica, and by the squat bell tower in red sandstone, uncompleted, carved with the date 1683.
The interior has a single nave with a barrel-vaulted roof subdivided into five spans by pilasters and arches, with four side-chapels.
The presbytery itself, which is very deep, is covered by an octagonal cupola (planned in the opening years of the 19th century by the architect Domenico Franco) and finished by a semi-circular apse, separated from the nave by a marble balustrade.
The high altar is also of marble of the 17th century, crowned by statues of Our Lady of the Immaculate Conception and of Saints Emilius and Priamus, patrons of the town.