The altarpiece of the Cathedral Basilica’s main altar has three parts. The first, somewhat higher up than the others, bears a symbol of Divine Providence, above which there rises a cross with the figure of Christ. The second part features an elaborate tabernacle.

A tabernacle is an ornate box meant to hold the Most Blessed Sacrament. The Cathedral tabernacle was decorated with the scenes portraying the events of Holy Thursday: the Last Supper, Jesus washing the feet of his disciples, and his prayer in the Garden of Olives. Above the tabernacle there is a domed niche for a cross or a monstrance, beside which there are the statues of St. Casimir and St. Stanislaus – the patron saints of Lithuania and the diocese of Vilnius.

The new altar, where Holy Mass is now celebrated, was installed in 2007 in line with the indications of Vatican Council II.