The cathedral was erected in the early 12th century in a Romanesque style, with Gothic, Baroque and Neoclassical elements.

In 1129 Bishop Peter III commissioned a new edifice in the latest architectural style from Raimundo, a local architect and builder.

The cathedral has a Latin Cross structure, with a length of 85 m. It has a nave, covered by a barrel vault, and two aisles, with an ambulatory and five apse chapels.

The façade is a Renaissance design by Julián Sánchez Bort [es] inspired by a plan proposed by Ventura Rodríguez for the Cathedral of Pamplona.

To the right of the entrance is the Gothic Torre Vella (bell tower), surmounted by a Renaissance top floor finished by Gaspar de Arce in 1580.