He was born in Sambor, obtained a law degree from the Jan Kazimierz University in Lviv, and a degree in economics in Poznań (some sources say that he also graduated from the University of War – Wyższa Szkoła Wojenna). In 1914–1917 he served in the Legions and then in the Polish Military Organisation (POW). Thanks to his connections in the town of Bialystok, after Poland regained its independence, Piasecki headed the local Tax Chamber in Białystok and managed the local Legionnaires Association. In 1922–1924, he was a secretary to the Speaker of the Senate. Associated with the Christian Agricultural Party (ChSR), he was involved in socio-political journalism and conducted historical and legal research. In 1928, he became a deputy to the Seym from the BBWR list (Non-Partisan Block for Cooperation with the Government) and was elected as the secretary of the BBWR parliamentary caucus. He died in Otwock.