Purpose. We continue our retrospective investigations of radioactive contamination of wild mushrooms from Ukrainian Polesie. The aim of the current study is an assessment of radioactive contamination of wild mushrooms from some locations of Chernihiv Polesie in 1991-2021. Methodology. A study of radiocaesium activity in 66 wild mushroom species (edible, inedible, conditionally edible, poisonous) (from 2 to 25 fruitbodies per sample) and soils (0-5 cm of upper mineral layer, taken by the envelope method) from 14 locations of Chernihiv Polesie was carried out with γ-spectrometry (Ge-detector Canberra GLX 4019, USA). In some mushrooms, 90Sr activity was determined radiochemically on the basis of 90Y accumulation according to the standard method. Scientific novelty. The results of γ-spectrometric studies of the activity of radiocaesium in 66 species of wild mushrooms from the localities of Chernihiv Polesie over a 30-year period are given, the coefficients reflecting the bioaccumulation activity of each species counted, the hyperaccumulator species of radiocaesium are determined, and the potential annual equivalent doses for adults are calculated under the conditions of consumption of some valuable culinary-medicinal mushrooms (B. edulis, C. cibarius, I. badia, Suillus spp, T. equestre). Conclusions. Activity levels of 137Cs in wild mushrooms of Chernihiv Polesie varied over the years 1991-2021 depending on the mushroom species, its ecological affiliation, radioecological situation at the sampling sites, showing a certain tendency to decrease over time. Hyper-accumulative properties in relation to 137Cs are demonstrated by Cortinarius, Sarcodon, Paralepista, Tricholoma, Lactarius, Suillus spp. Widely distributed on the territory of Ukrainian Polesie - I. badia, P. involutus and L. rufus, remain representative bioindicators of radiocaesium contamination. A potential calculated annual effective doses due to the mushrooms consumption by adults, considering only the effect of the 137Cs, reached a high values in Suillus spp., T. equestre, and I. badia – 0.041, 0.035 and 0.025 mSv, respectively, which indicates a relatively insignificant dose load when consuming mushrooms in these localities compared to other localities of Ukrainian Polesie that have higher levels of soil contamination with radionuclides. However, radiation monitoring can still be recommended during mushroom procurement and mass collections.