[en] The radioactivity monitoring in the 'Nikola Tesla' thermo-electric power plant environment comprised the analysis of soil, waters, flying ash, slag and plants. Soil, plant and water samples were taken in the environment of the 'Tent A', 'Tent B', 'Kolubara' and 'Morava' power plants during the two years period 2003-2004 and analyzed b y standard radiometric methods. Naturally occurring radionuclides 226 Ra, 232 Th, 40 K, 235 U, 238 U, 210 Pb are determined by gamma spectrometry using H.P. Ge detector, relative efficiency of 23% and energy resolution of 1.8 keV (1332.5 keV). Certified reference materials: soil matrix with 55 Na, 57 Co, 60 Co, 89 Y, 133 Ba and 137 Cs (MIX-OMHSZ, National Office of Measures) and grass with 134 Cs, 137 Cs, 40 K and 90 Sr (IAEA-373) were used for calibration. The gross alpha and gross beta activity measurements are carried out using low-level background alpha-beta proportional gas counter. Radiochemical analyzes of soil samples have shown the naturally occurring radionuclides: 226 Ra 35-60 Bq/kg, 232 Th 35-49 Bq/kg, 40 K 513-711 Bq/kg, 210 Pb 14-69 Bq/kg, 238 U 25-80 Bq/kg and 235 U 1.1-4.5 Bq/kg. The 137 Cs was found in concentration 10-57 Bq/kg. Radiochemical analyzes of plant samples have shown the naturally occurring radionuclides: 226 Ra 0.7-6.1 Bq/kg, 232 Th 1-4.8 Bq/kg, 40 K 392-1132 Bq/kg, 210 Pb 5.6-97 Bq/kg, 238 U 2.3-7.4 Bq/kg and 235 U 0.2-0.7 Bq/kg. The 137 Cs was found in concentration 0.13-2.8 Bq/kg. The water samples were within the range of recommended values for drinking waters in Serbia and Montenegro. Total alpha activity was below the lowest limit of detection and total beta activities were up to 0.35 Bq/l. The results of measured radionuclides in soil, plant and water samples do not show any significant radioactive environmental pollution. (authors)