The ornamentation of the Church is divided into two large areas: the pictorial and imagery decoration and that of the stained glass windows.

The interior of the Church is abundantly decorated on the walls, roofs and crowning. The walls are complexly painted and decorated with gilded moldings that frame the panels, in the Boiserie European XVIII Century style, also supplemented by gilded molding discs. These are tied to the decoration of scallop trims, floral and vegetation elements. The roof has rich fresco paintings made by the Cabral Brothers, where there are abundant angelical scenes, as per the name of the church.

The dividing columns of the naves are decorated in their shaft with brown marble-type painting that hold semicircular arches decorated both in their intrados as well as their extrados with gilded garlands. Between the arches, gilded molded triangles can be seen with white vegetation decorations. In the upper part, the frieze and cornice can be seen also decorated with scallop trims and architectonic elements, supporting the cannon vault that is completely decorated by holding panels with vegetation ornamentation and garlands that accompany the central discs with Fresco paintings dedicated to biblical and angelical scenes.

The transept has devotional altars on each end. On the left looking towards the high altar the decoration is dedicated to the Sacred Heart of Jesus. In its central part it is formed by a sculptural work of the Sacred Heart of Jesus, adorned in the back by a pictorial work dedicated to the Birth of Jesus. On the other side, there is an altar dedicated to the Guardian Angel, the reason behind the naming of this temple. The altar is formed by the sculpture ensemble of the Guardian Angel accompanied by a child and adorned in the back by a pictorial work dedicated to the Virgin with Baby Jesus in her arms surrounded by angels on the top. Both altars are decorated in a similar manner: in a symmetric manner. They have decorations in the molding panels decorated with garlands, scallop trims and gilded hanging figures that crown the semicircular arches. There, there is a key voussoir transformed into a gilded winged angel on the top.

The lateral naves have a lintel roof formed with small celestial truncated domes that are decorated in a light blue background with a golden stared decoration. Among the domes the decoration of the gilded molding panels with central discs can be appreciated. The lateral walls are decorated in a similar manner as the division of the naves, i.e. pilasters that support molding semicircular arches. These arches surround the other type of decoration in this temple, i.e. stained glass windows.

The set of stained glass windows of the Church of Los Ángeles Custodios are of painted and furnace-heated glass dating from 1898 and derived from the Zetler German workshop, famous for creating a style defined as “Munich” in the production of stained glass windows.

In the lateral naves there are 5 stained glass windows on each side, plus two in the skylight and two in the transept altars. The stained glass windows of the lateral and vertical naves are topped with semicircular arches, and are dedicated to the Intellectual Saints who with their studies contributed their theological knowledge, also called the “Doctores de la Fe” (Doctors of the Faith). Looking towards the high altar, in the lateral left nave, there are stained glass windows dedicated to: Saint James the Great (better known as Santiago the Great), the first man to follow Jesus and one of His three Apostles who witnessed the transfiguration and the Agony of the Lord in the Orchard of Gethsemane; Saint Francis de Sales, author of the Introduction to the Devout Life and Treatise on the Love of God; Saint Alfonso de Ligorio, founder of the congregation of the Redemptorists in 1732 and author of the Moral Theology and Las Glorias de María; Saint Toribio, Archbishop of Lima in 1579 who drafted the catechism in the autochthonous tongues Quechua and Aymará; and Saint Agustin, the most eminent of the Christian theologians.

In front, there are stained glass windows dedicated to: Saint Michael Archangel, appointed as the head of angels, who defeats Lucifer with his contingent placing him, at his feet, with a spear over him; the Guardian Angel, protection symbol of the innocents; Saint Thomas of Aquino, one of the most important and influential figures of Christian thought, author of the recognized “Summa Theologica”. He is depicted with his characteristics symbols: the sun on his chest, the dove that comes to him and he holding a red book in his hand; Saint John the Evangelist, the youngest of the four evangelists and organizer along with Saint Peter of the primitive Christian church; and Saint Charles Borromeo, who was responsible for starting the reform of the clergy and the final deliberations of the Council of Trent, and the Bishop of Milan. In the stained glass window it can be seen that he has a model of the Cathedral of Milan in his hands.

The stained glass windows located on the top of the transept, adjacent to the dome, are horizontal and topped in a semicircular arch dedicated to the life of Jesus. The first window has the following caption “Let the children come to me,” where Jesus asks that they let the children come to him. On the front is the following, “Christ gives the keys to Peter,” where the image of when Apostle Peter is given the keys of the kingdom is depicted.

Two circular-form stained glass windows are located in the roof of the altars of the transept with angelical scenes, which illuminate the space of the lateral altars.