This large cathedral, with prominent twin spires, is off Kenyatta Road in the Baghani part of town. Although its spires are a major landmark from a distance, the cathedral can be surprisingly hard to find in the narrow streets. It was built between 1893 and 1897 by French missionaries and local converts, who had originally founded a mission here in 1860.

The plans were drawn by the same French architect who designed the cathedral in Marseilles, France. The tiles and the stained-glass windows were imported from France, and the murals on the inside walls, painted just after the cathedral was completed, also show a clear French influence.

Unfortunately, some of the murals have recently been badly restored. The cathedral is in regular use by the town's Catholic community, a mixture of Zanzibaris, Tanzanians from the mainland, Goans and Europeans. There are several masses each Sunday, and one or two on weekdays too. Outside mass times, the main cathedral doors may be locked, and entrance is via the back door reached through the courtyard of the adjoining convent.