The Polesie State Radioecological Reserve (PSRER; Belarusian: Палескі дзяржаўны радыяцыйна-экалагічны запаведнік, romanized: Palyeski dzyarzhawny radyyatsyyna-ekalahichny zapavyednik; Russian: Полесский государственный радиационно-экологический заповедник, romanized: Polessky gosudarstvenny radiatsionno-ekologichesky zapovednik) is a radioecological nature reserve in the Polesie region of Belarus, which was created to enclose the territory of Belarus most affected by radioactive fallout from the Chernobyl disaster. The reserve adjoins the Chernobyl Exclusion Zone in Ukraine. The environmental monitoring and countermeasure agency, Bellesrad, oversees the agriculture and forestry in the area.