The Parish of the Most Holy Trinity in Zambrów is a Roman Catholic community that was established on May 4, 1283, through the foundation of Duke Konrad II. The history of the parish is turbulent; in the 13th century, during numerous Russo-Lithuanian-Polish conflicts, the parish was suspended but was reinstated by Duke Janusz I at the end of the 14th century. The current church, built in the Neo-Gothic style, was constructed between 1874 and 1879 on the initiative of priests Paweł Makowski and Aleksander Mioduszewski, and its consecration took place on June 4, 1925. The architecture of the church features preserved epitaphs, such as those of Maciej Laskowski and Mateusz Krajewski, as well as valuable liturgical objects, including a Baroque monstrance and a Rococo chalice. The church was destroyed during World War II but was rebuilt thanks to the efforts of Father Aleksander Srzednicki. The parish has a cemetery covering an area of 4.0 hectares, located 0.5 km from the church. The rectory, a masonry building, was constructed between 1986 and 1988. Throughout its history, the parish has had many pastors, with the earliest being Father Marcin of Idzikowice around 1445. Many changes in leadership were related to historical events, as well as the personal lives of the priests who served their roles, nurturing the spiritual and material development of the community. The Parish of the Most Holy Trinity not only centers religious life but also plays an important role in the local culture of Zambrów, serving as a significant reference point for its residents.