Zdunek [ˈzdunɛk] is a village in the administrative district of Gmina Myszyniec, within Ostrołęka County, Masovian Voivodeship, in east-central Poland. It lies approximately 6 kilometres (4 mi) south-west of Myszyniec, 34 km (21 mi) north-west of Ostrołęka, and 126 km (78 mi) north of Warsaw.