Pierzchnia [ˈpjɛʂxɲa] is a village in the administrative district of Gmina Stara Błotnica, within Białobrzegi County, Masovian Voivodeship, in east-central Poland. It lies approximately 6 kilometres (4 mi) north-west of Stara Błotnica, 8 km (5 mi) south of Białobrzegi, and 71 km (44 mi) south of Warsaw.