Since 1998, the Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise 'G. Caporale' in Teramo is conducting radioecological surveys in the Abruzzo region (Central Italy), to acquire knowledge on the geochemical and biological mobility of radionuclides derived from the Chernobyl accident. To this end, samples of grasses, fungi, mosses and soils were collected in four national parks (Sirente-Velino, Abruzzo Lazio and Molise, the Gran Sasso and the park of Monti della Laga and Maiella). The results show that the Chernobyl fallout is still detectable in the samples collected in the four parks but the (137)Cs concentrations are present in the semi-natural environments in quantities that do not create concerns from a radiological point of view.