The first wooden temple was built in this place, according to tradition, already in the 13th century. Another brick church consecrated in 1408 burned about 1470. The present building was erected in 1474 from the foundation of the parish priest of Przasnysz, Michał Bończ-Boniecki and about 1489 consecrated by bishop Piotr of Chodkowo. Almost simultaneously with the church, two side chapels were built: the northern one funded by the tailors and the south, called Our Lady, of the foundation of Jan Kostka from Rostków. A large porch from the west was probably built in the first half of the 16th century.
In the seventeenth century the parish church divided the fate of Przasnysz and was destroyed several times by fires. Rebuilt after the fire of 1645, was consecrated in 1670 by the Poznań bishop Maciej Kurski. After the fire of 1792, the church remained in ruins for over half a century. Reconstruction was made between 1848-56 and then in 1877-1878. The eight pillars of the nave were removed, the western façades and porches formed, the sacristy and the treasury were rebuilt, the porch was added to the south chapel, and the interior of the church was covered with an apparent barrel vault.
The church was built in gothic style. It is brick built, orientated and has single nave. It has a separate, straight ended chancel and a pair of two-span side chapels. A rectangular vestry and treasury is adjacent to the chancel. At the chancel arch from the north there is a circular staircase, covered with a pyramid roof. The roofs of the nave, the chancel and the western porch are gabled, over the chapels and the vestry are mono-pitched roofs. The nave is covered with a ceiling, in the chancel was once a diamond vault, and in the chapels rib vaults.
Next to the church rises a stand-alone, gothic, brick bell tower, probably from the end of the 15th century. In the 16th century it was elevated by the third floor.
Żabicki J., Leksykon zabytków architektury Mazowsza i Podlasia, Warszawa 2010.
Website wikipedia.org, Kościół Wniebowzięcia Najświętszej Maryi Panny w Przasnyszu.