Shortly after the completion of the cathedral, a 49-meter six-level bell tower was erected to the northeast of it. On the second tier, in the niches of the southeast and northwest corners of the square, there were sculptures of the Evangelists. The baroque decor of the bell tower, made in bright colors, was as beautiful as the cathedral itself. Under each of the eight windows of the bell tower's "lantern," blue tiles with yellow and white star-shaped patterns were placed in square recesses. Above each window on all tiers of the bell tower were white stone kokoshniks.

In 1888 and 1890, clocks made by Pyotr Ionovich Klimov were installed on the penultimate tier. Before the revolution, there were ten bells on the bell tower. The largest of them had the inscription: "In the blessed reign of the Most Pious Sovereign Emperor Alexander Pavlovich and all Russia, with the blessing of the Most Reverend Ambrose, Archbishop of Kazan and Simbirsk, and various orders of knights, this bell was recast in the reigning city of Kazan for the cathedral church of the holy apostles Peter and Paul. Weighing 189 poods and 34 pounds. 161 poods of metal came from the previous broken large bell, and the rest was added, as well as the payment for the recasting, collected from generous donors. This bell was cast by the Kazan merchant Ivan Efimov Astrakhanets in 1825."

On the second bell, the inscription read: "This bell was cast in the reigning city of Kazan, at the factory of Seryi Kornilov, for the church of Peter and Paul, donated by Peter and Nikolai Molostvov and with the diligence of the parishioners and the efforts of the priest Viktor Petrovich Vishnevsky and the church elder, Kazan merchant Savely Stepanovich Zaytsev, on June 10, 1835, weighing 99 poods."

On the third bell, it stated: "Come, people, to the Temple of the Salvation of our God. Cast by master Pyotr Nikitin Kiryukhov. Weighing 54 poods and 17 pounds."

On the fourth bell, weighing 15 poods and 11 pounds, there were bas-relief icons: to the east, the Exaltation of the Cross by Constantine and Helena, to the west, the Crucifixion, to the south, the Kazan Icon of the Mother of God, to the north, St. Nicholas the Wonderworker. The inscription read: "This bell was cast in Kazan, at the factory of Ivan Kiryukhov." The pre-revolutionary bells were destroyed, but recently a new 3-ton bell of Yaroslavl casting, similar to the one that existed before the revolution, was installed on the bell tower.