Each year on September 30, in accord with liturgical law, the Anniversary of the Dedication of St. Joseph Cathedral is celebrated in the Diocese of Baton Rouge.Within the Cathedral itself it is celebrated with the rank of Solemnity, even when it falls on Sunday; elsewhere in the diocesan territory it is observed with the rank of Feast, except when it occurs on Sunday.

The last formal Dedication of the Cathedral occurred in 1970, when the post-Vatican II renovation of the present church building was completed, a project which began in 1966 and was not completed until 1970. These renovations including the blessings of a new high altar, ambo, cathedra and baptistery; at this time the building was also air-conditioned for the first tme, the interior brickwork was renewed and cleaned, and a new steeple installed. Artwork by Ivan Meštrović (crucifix and Prodigal Son statue), Frank Hayden (Holy Family statue), Milo Piuz (tapestry), and Adalié Brent (sacristy stained-glass windows) was added to the building as well.

The principal celebrant of the Mass of Dedication in 1970 was the Most Rev. Robert E. Tracy, D.D., LL.D., the first Bishop of Baton Rouge, with His Eminence John Patrick Cardinal Cody, J.C.D., the Archbishop of Chicago, presiding in choir and preaching.

In remembering the Dedication liturgically each year, white vestments are used, and the Gloria and three readings from Sacred Scripture taken from the Common of the Dedication of a Church in the Roman Lectionary are proclaimed; the Creed is recited at the Cathedral itself.