In the interior, the church is formed by three naves separated by semicircular arches. The central nave is formed with a cannon vault, while the lateral naves are of a post and dintel construction with on-sight frames that are crowned in its walls with gabled windows in order to have the exterior light come in. The separation of the naves is made by pillars holding large semicircular arches, from which lamps for interior lighting hang. The construction is made with blocks of on-sight stone without coating, which gives it an important aspect of sobriety.

Through the lateral naves there are square niches that in some cases are crowned in semicircular arches made in the same stone construction, and are used as altars for the devotion of certain religious figures that are separated by construction buttresses in order to reinforce the walls. The following sculptural ensembles can be mentioned starting from the lateral left nave: the Virgin del Carmen, and Saint Martín de Porres. Towards the back, next to the high altar, there is an ensemble of three figures: in the center is Santa Rosa, with San Francisco on her left and Santo Domingo on the right.

In the lateral right nave there is: The Crucifixion, Saint Pancracio, and Saint Teresa, the first Chilean Saint. On the back, next to the high altar, there is an altar dedicated to the Holy Sacrament.

Located in the high altar there is an image of the Virgin del Rosario, or also known as the Virgin de Pompeya, which is venerated in this temple. She is crowned with a large figure of Jesus crucified hanging from the roof, and a central sky light that illuminates the high altar, giving the whole ensemble a dramatic daunting character.

Without a doubt one of the interesting points of this temple is the construction type, with on-sight material, lacking any ornament, and the simplicity of its terminations convey the sensation of a construction that has remained standing throughout time, despite the ravages of time, and the dramatic layout of its figures that have been spectators of all the evolution process of this church.