Piątkowizna [pjɔntkɔˈvizna] is a village in the administrative district of Gmina Łyse, within Ostrołęka County, Masovian Voivodeship, in north-eastern Poland.

[2] It lies approximately 43 kilometres (27 mi) north of Ostrołęka and 143 km (89 mi) north of Warsaw.

The village was founded in the 18th century.

[3] As of 1827 it had a population of 208, solely Kurpie, a local subgroup of the Polish people.

This Ostrołęka County location article is a stub.