The steel superstructure of the edifice was a unique form of construction for the times. Massive stone supports were used together with the steel. The church stands 112 feet high. It is 136 feet long and 85 feet wide. The structure can accommodate over a thousand worshippers.

Enter the Cathedral at Oakley and Rice Streets in Chicago and your eyes are arrested by a brilliant panorama of heaven. Glorious figures and scenes fill the windows, walls, ceiling and apse of the edifice. The casual visitor is struck by the splendor within the stately structure.

The vaults and arches of the cathedral thrust worshippers heavenward, particularly because of the profusion of various shades of blue and gold. The harmonious combination of color and ornamentation carries through the entire church and complements the browns of the Italian marble on the sanctuary floor, the wainscoting around the cathedral, the tetrapod, the cathedral throne and iconostasis. Like the twelve apostles, the twelve sturdy columns support the broad cathedral roof and provide and appearance of strength to the church. Four minor side columns remind the worshippers of the four evangelists.

The dominant icon representation at the front and top of the interior wall above the altar is the Pantocrator (Lord of all), together with the Theotokos (Godbearer), St. John the Forerunner and Baptizer, St. Nicholas the Wonderworker, bishop of Myra in Lycia and Holy Hieromartyr, St. Josaphat of Polotsk (the first Ukrainian Catholic saint). Symbolically, at the far left and right, are the domes of the Cathedrals of St. Sofia in Kyiv and St. George in Lviv, as if to remind the faithful of their ethnic origin.

The central dome in the center of the Cathedral is covered with gold and a wide bank of six-winged angels. On the side walls, a powerful representation of the descent of the Holy Spirit is depicted on the left and the Dormition on the right. Four sections of the main dome portray the four Evangelists who symbolically support the entire central portion of the church. The spiritual pillars of the Eastern Church appear on either side of the ceiling: St. Basil the Great, St. John Chrysostom, St. Gregory the Theologian and St. Gregory Nazianzen. At the back of the Cathedral above the choir loft, one can find the icons of the two great apostles of the Slavs, the saintly brothers, Cyril and Methodius.

All the windows contain stained glass depictions of Old and New Testaments themes created in traditional Byzantine Ukrainian style by the Munich Studios of Chicago. The north and south walls prominently display scenes of the Nativity and Transfiguration of the Lord. Equally beautiful are the windows in the back of the church depicting the Last Judgment.

Hanging from the central dome of the Cathedral, is a massive nine-tiered gold chandelier, lit by 480 individual globes. It was specially designed by Greek craftsmen and was reputed to be the largest of its kind in the country at the time of its installation.

The iconography, masterful work of Boris Makarenko and Myron Bilinsky of Philadelphia, is also in Byzantine Ukrainian style, using bright colors reminiscent of the iconography of Kyiv’s St. Sophia, the mother church of all Ukrainian Christians.

The entire sanctuary floor is a single level covered in Italian marble. The wainscoting around the church matches this marble. The altars of proskomedia and vesting are of the same material, as well as the cathedral chair and apsidal seating. Even the iconostas is made of marble.

Several mosaics grace the Cathedral. The “Oranta” Mother of God and the whole Eucharistic composition cover the apsidal wall. Delicate mosaic Stations of the Cross are mounted on either side of the church. All the art harmoniously complements the extensive marble elements and add to the solidity and structural permanence of the church.

The exterior west wall of the Cathedral bears a unique mosaic icon of St. Nicholas, patron of the Cathedral. The portal beneath is adorned with a mosaic representation of a famous miraculous Ukrainian icon, Our Lady of Pochaiv. This beautiful icon was designed by Boris Makarenko and made in Italy.