[3] He was ordained a priest on 25 May 1980 in the cathedral basilica of the Nativity of the Blessed Virgin Mary in Tarnów by the local diocesan bishop Jerzy Ablewicz.

From 1984 to 1985, he papered for missionary work at the Mission Formation Center in Warsaw, and then, for five months, he studied French at the Alliance Française school in Paris.

From 1997 to 1998 and 1999 to 2000, he worked as a pastor in the parish of Santa Maria de Huachipa in the suburbs of Lima in Peru.

In the years 2006–2010, he gave lectures commissioned on the history of missions and papal missionary works at the Cardinal Stefan Wyszyński University in Warsaw.

[1] Piotrowski chose "In Caritate Evangelium Prædicare" (To preach the Gospel in love) as his bishop's motto.

[7] On 11 October 2014, Pope Francis appointed Piotrowski as the new bishop of Kielce, replacing the retiring Kazimierz Ryczan.