The church, which is accessed through a porticoed courtyard, has a rectangular plan with three naves divided into four sections, separated by octagonal pillars with moulding that support on pointed arches. The naves are covered with a panelled coffered ceiling with Mudejar decoration in the central nave and a hanging ceiling on the side naves.
Although the 15th-century temple is in the Gothic-Mudejar style, it has been extensively renovated in the 17th and 18th centuries, including the Monteros Chapel on the right wall, decorated with plasterwork from 1630, and the Sacristy, rebuilt and decorated by Páez de Carmona in the second third of the 18th century. The Chapter House and the Vestry are also from the 18th century, as are the Baptismal and Sacramental chapels.
Highlights inside the Church include the main altarpiece, from the second quarter of the 16th century, which contains paintings by Alejo Fernández and a group of sculptures representing Santiago and scenes from the Passion of Christ, and other small images located on the columns separating the aisles. The ensemble is completed with the altarpieces in the side chapels. The altarpiece in the left chapel houses the Christ of the Expiration, sculpted by Pedro Roldán around 1685, and a group of paintings by Pedro de Campaña and his studio from the mid-16th century. And, the 18th century bust of Our Lady of Sorrows and a 16th-century bas-relief showing the Annunciation on the right altarpiece.
The 50-metre tower was built over the remains of the previous tower from the 15th-16th century, destroyed in the 1755 earthquake. The brick tower consists of a shaft with three tapering tiers topped by a small dome, which gives the tower a slender and soaring form. The decoration combines carved brick mouldings and capitals, stone elements, painted plaster, blue glazed ceramics, pilasters, estipites, etc., creating a polychrome effect that contrasts with the brick of the shaft.