He specializes in Polish-Ukrainian relations during WWII as well as in the history of Polish resistance (primarily of Armia Krajowa) in the former eastern Polish regions (Kresy), as well as the history of totalitarian systems.
Polish historian Rafał Wnuk of the Institute of National Remembrance in Lublin categorized Poliszczuk's work as belonging to the "para-scientific" tradition along with some other Polish authors who are "neither scientific nor objective".