The Basilica, which is in the form of a Latin cross, is a classic example of Gothic style which can be described as “Franciscan” because it avoids the pomp and ostentation of the spires, pinnacles and flying buttresses of Gothic style while highlighting the harmony, beauty and simplicity of the lines. The name of the architect is not known because in 1369 many precious and ancient documents were burnt in a fierce fire which destroyed most of the convent and part of the church.
The external length of the Basilica is 102 metres, the width is 32 metres. The transept measures 48 metres and is 16 metres wide. The height is 28 metres both from the central nave and from the transept.
The facade of the Basilica is extremely impressive, split into three parts by simple pilasters in late Gothic style. The central part of the facade is adorned with a portal with splays which are flanked by two precisely-worked white pillars. At the top of the ogival arch, there is the Christ Resurrected by Alessandro Vittoria (1581) while on the left there is the Virgin Mary with the Child and on the right St. Francis, statues carved by Bartolom eo Bon (slightly after 1430). In the lunette the outline of the fresco of Gaetano Zompini (18th century) remains. This represents the Virgin among the angels. Level with the aisles, there are three circular windows in white Istrian stone. the one, in white, on the left bears the lion of Venice and the lily of Florence in the etched cornice to indicate that the chapel of the Fiorentini is on the inside. The one on the right is smaller and in two colours and bears the figure of St. Anthony, indicating the chapel of the same name on the inside.