Żmijówek Włościański (Polish pronunciation: [ʐmiˈjuvɛk fwɔɕˈtɕaj̃skʲi]) is a village in the administrative district of Gmina Troszyn, within Ostrołęka County, Masovian Voivodeship, in east-central Poland. It lies approximately 7 kilometres (4 mi) south-east of Troszyn, 18 km (11 mi) south-east of Ostrołęka, and 102 km (63 mi) north-east of Warsaw.