It stood where a Lombard ducal chapel was probably built. After the construction work was completed in 1285, it was also used for meetings of the popular assemblies, where municipal matters were discussed.

In 1917, during the retreat of Caporetto, it was set on fire and subsequently restored several times.

The church gives its name to the square it faces; the gabled façade is very simple, as was typical of many Franciscan churches, with a portal surmounted by a large niche. 

To the left of the façade, the bell tower is in Romanesque style; it has a square plan and features four mullioned windows, one on each side, in the bell chamber. The apses, which can be seen very well from the nearby Ponte del Diavolo, are very tall, as was characteristic of the Gothic style.

On the right side of the square is the Palazzo Pontotti Brosadola, built around the mid-18th century, characterized by a very simple but harmonious façade; inside there are interesting frescoes by Francesco Chiarottini.

The interior of the church has the typical Gothic structure with a single nave and a truss ceiling, restored several times over the centuries.

Numerous and different artists, all unknown, who worked in San Francesco from the beginning of the 14th century until the first half of the 16th century, have left numerous fresco remains.

Among these are attributed to the followers of Vitale da Bologna, who worked in the nearby Duomo of Udine:
• Redentore in mandorla;
• Madonna in trono;
• Annunciazione;
• Crocifissione

In addition to these, there is an Adorazione dei magi, a large composition attributed to a follower of Altichiero, and some Saints present in the transept, of the Rimini school. A tomb with a unique coat of arms dating back to 1230 is located in the left corner of the presbytery.

In the sacristy, there are frescoes by Giulio Quaglio the Younger dating back to 1693, stuccos by Retti, and furniture by Giacomo Brollo from Gemona from 1694.