The center doors lead into the main aisle of the Nave.  The Cathedral nave consists of a large, clear space with a cruciform (cross shape) floor plan.  It is illuminated be magnificently glazed tracery windows.

St. Agnes Cathedral’s bright red, blue and green ceiling is the work of liturgical architects, Rambusch Associates of New York City and was part of the cathedral’s renovation completed in the Spring of 1982. The colors, which also represent liturgical colors, form a scarlet cross that stretches from the rear of the cathedral to the front. The cross' center is directly over the main altar.  Red, blue and green colors can also be found in many of the cathedrals stained glass windows and a purpose of  the ceiling design is to accentuate the windows.  Beautifully hammered iron chandeliers, hang in two rows on long chains from the tiled ceiling. 

Six pointed arched trusses springing from carved stone corbels built into the side walls support the ceiling.  At the point where each arch meets the ceiling is a shield.  Twelve in all, one for each apostle.  The apostles and their emblems are as follows: