The cathedral appears in one of the earliest color photographs ever taken by Louis Arthur Ducos du Hauron in 1877.

[2] The main organ built by Stoltz featured in the Universal Exposition of 1855 in Paris,[3] according to legend, offered by the Empress Eugénie in 1858 to the cathedral of Agen that hitherto had no instrument.

It is a nationally listed historical monument and so too is the choir organ built by the makers Magen in 1885, with 15 registers, two manuals and a pedal-board.

Interesting architectural features include the Romanesque apse which is extended by a Gothic frame along a single nave.

The cathedral's nave is much shorter than might be expected judging from the size of the chancel: this was the consequence of earlier political and financial difficulties.