The size and quality of the instrument ranks it among the largest and best 17th century organs. It has over 6 thousand pipes, 74 speaking stops altogether, including a sixteen foot principal; 20 ranks of mixtures, including a Polish cymbal of 7 to 10 ranks, which speaks in the range of 1/5, 1/6, 1/7 and 1/8 foot pitches (all placed on a common foot). The organ boasts on open 32 foot pedal stop, one of a very few world-wide built during the 17th century.

An unusual characteristic of this organ is the wide spatial distribution of its sections. The main division measures 50 ft high and 25 ft wide. Because of that the action mechanism is very complex and required the highest craftsmanship from organbuilder. The Lezajsk organ has a tracker action system, which means keys and pedals are mechanically linked with valves. Special effects such as tympani and the bird stops make a separate division located on the main aisle pillars. Two positives in the side aisles crown the appearance of the loft. Independent from the big organ and relatively smaller, together create a unique monumental organ complex, where three organists can play simultaneously.

The Baroque ornate case of the instrument has no equal. The Lezajsk organ is unique for its figures that adorn and surround it. Two monks of Lezajsk’s monastery: L. Franciszek and the initiator O.T. of Buczacz carved the sculptures and its rich Baroque decorations.

Later changes and preservation
1852 Roman Ducheński added two flute stops made of bamboo.
1903-1906 Aleksander Żebrowski modified thetracker with Barker levers, installed new consoles and romanticized the specifications.
1967 Robert Polcyn restored the organ’s Baroque character.
2000-2003 A thorough renovation led initially by the French company Manufacture Provençale d'Orgues, and then the organ master Adam Wolański of Poznan (Poland)

Recent restoration returned the organ to its original musical values retaining its pleasing aesthetic and architectural condition.