ABSTRACT. Radiocarbon is produced in all types of nuclear reactors. Most of the 14 C released into the environment is in the form of gaseous emissions. Recent data on the 14 C concentration found in terrestrial samples taken in the vicinity of nuclear power plants in Romania and Lithuania are presented. We found increased 14 C levels in the surroundings of both power plants. At the Romanian power plant Cernavoda, we found excess levels of 14 C in grass within a distance of about 1000 m, the highest 14 C specific activity being 311 Bq/kg C (approximately 28% above the contemporary 14 C background) found at a distance of 200 m from the point of release (nearest sampling location). At the Lithuanian power plant Ignalina, samples of willow, pine, and spruce showed a 14 C excess of similar magnitude, while significantly higher values were found in moss samples. The samples were analyzed at the accelerator mass spectrometry facility in Lund, Sweden.