The Basilica del Pilar stands out for its imposing exterior volume, which has grown over the centuries, especially since its Baroque period, with the addition of domes and towers. It currently has eleven domes covered with glazed tiles in shades of green, yellow, blue and white. The main dome is located in the center, where the nave and the central section of the church, which consists of three naves and seven bays, cross. On both sides there are two medium domes, over the Holy Chapel and the Main Choir, accompanied by four smaller domes in the angles. In addition, between the buttresses there are chapels topped with lanterns. The towers, designed in the 20th century by the architect Miguel Ángel Navarro Pérez, reach 98 meters in height.

In 1944 a popular collection was promoted to reform the south façade, which overlooks the square. The project, executed between 1945 and 1950 by Teodoro Ríos, framed the two side doors with porticoes of triangular pediments supported by Corinthian columns. Pilasters were also added to break the uniformity of the wall and a central portico was created, aligned with the main dome, which includes a niche with the sculpture of the Coming of the Virgin, the work of Pablo Serrano in 1969. On the sides, niches were placed with flambeaux and, at the top, a large molded cornice and a balustrade with statues of Aragonese saints, made by Félix Burriel and Antonio Torres Clavero.

On the eastern façade, next to the door closest to the Santa Capilla, the Romanesque tympanum was preserved, the only visible vestige of the old medieval church. In addition, the north and east facades still show the impacts of the bombs dropped by the French troops during the sieges of Zaragoza in 1808 and 1809.