Ościsłowo [ɔɕt͡ɕiˈswɔvɔ] is a village in the administrative district of Gmina Glinojeck, within Ciechanów County, Masovian Voivodeship, in east-central Poland.[1] It lies approximately 12 kilometres (7 mi) east of Glinojeck, 13 km (8 mi) west of Ciechanów, and 79 km (49 mi) north-west of Warsaw.
During the German occupation of Poland (World War II), Ościsłowo was the site of large massacres, in which several hundreds of Poles were murdered as part of the Intelligenzaktion.[2] Also several dozen disabled from the region were murdered in the village on 20 February 1940.[3]