Between 1715 and 1723 Niesiecki worked as a preacher in Masovia, Greater Poland, Lesser Poland and Ruthenia. He taught rhetoric in Bydgoszcz and Chojnice, and ethics and mathematics in Kalisz. From 1724 he lived in the monastery of Krasnystaw, where he engaged in his life's work, compiling the Herbarz Polski (Polish Armorial). Niesiecki died there on 9 July1744.
The first volume of Herbarz Polski was published in 1728 in Lwów. Niesiecki wanted to write it in Latin, but his patron, Marianna from Potocki-Tar?owa, specified that it to be published in Polish. Because Niesiecki tried to not use unverified sources and legends, he was rubbished by the szlachta (Polish nobility). He continued with the work, however there were delays in printing the next volumes. After fourth volume was published attacks by the nobles increased; they sent letters of protest to his Polish and Roman superiors. Work on the fifth volume was interrupted by his death; it was completed by Stanis?aw Czapli?ski, but never published.