The Church of las Agustinas in its interior has a Basilica-type floor layout with three naves, its walls are painted in an apricot color with white areas and divided by fluted columns imitating the Corinthian style that hold semicircular arches.
The top part of the central nave is made in a reduced cannon vault completely adorned with biblical, and angelical scenes, and with architectonic decorative and symbolic elements such as discs, hanging decorations, scallop trims and floral ornaments. The ornamentation of decorative medallions in the ceiling can also be curiously appreciated, which are adorned with the “all seeing eye” symbolizing man searching for divinity in a spiritual hierarchy.
In the lateral naves, there is post and dintel construction, and there are altars with pictorial works that represent the cult of the parishioners, separated by the row of images of the Stations of the Holy Cross according to each station. The formation of the altars is of an architectonic ornamentation, framed by fluted columns of a Corinthian type and finished off by semicircular arches. Depending on the altar, the number of columns increase and it finishes change to a circular faltering pediment to top off at a greater height in a triangular pediment.
The altars of the ambulatory area do not have information on the representations it has; only some can interpret the figures due to the symbolism of the imagery.
Looking towards the high altar, on the left there are devotional altars: Saint Alberto Hurtado (that differently from the other altars, does not have a decorative architectonic construction, but rather a sculptural figure simple exhibited over a marble type cover. This might be due to the fact that the figure has been exhibited for a less period of time that the prior ones); sculptural ensemble dedicated to Saint Monica and Saint Agustín; canvas dedicated to the Virgin del Carmen accompanied by Saint John of the Cross and Saint Theresa; and the sculptural ensemble of the Crucifixion (the set shows the Virgin Mary, Mary Magdalene, Christ Crucified and God, crowning the altar). On the front there are altars dedicated to: Our Lady of Fatima; and Our Lady of la Merced. All exhibited in large altars with an architectonic decoration imitating Greco-Roman portico.
The high altar has a shrine which exhibits the Holy Sacrament, on Fridays, held by two angelical sculptural figures. The rest of the days of the week have a canvas dedicated to the Sacred Heart of Jesus. The apse is full of carved figures surrounded by religious symbols, immerse in wall niches topped by semicircular arches. All this high altar is crowned by a semicircular dome decorated with coffers that decrease in size as they come closer to the center.
The beautiful colonial XVIII century pulpit in a Baroque-Bavarian style is made in the workshops of the Jesuit priests of Calera de Tango. The original termination was fire-furnace decorated, but in order to restore it, it was done with gold paint.
Lastly, it has an organ from the Walker Company of four-hundred and ninety-two tubes, through which air is blown be means of a manual bellows lever.