The present study aimed to analyze the biological effects induced by bioaccumulation of uranium in Phaseolus vulgaris. Ten-day-old seedlings were exposed to 0, 0.1, 1, 10, 100 and 1000 µM U in diluted Hoagland solution. Following 1, 2, 4 and 7 days’ exposure, plants were monitored for uranium uptake, biometric parameters, capacities of enzymes involved in the anti-oxidative defence mechanisms, glutathione pool and DNA integrity. Uranium contents were up to 900-fold higher in roots as compared to primary leaves. For all enzymes studied, except SOD, enzyme capacities in roots were slightly stimulated with increasing contaminant concentrations (though not significantly). For roots exposed to 1000 µM U, enzyme capacities were significantly reduced. Enzyme capacities in leaves were not affected by uranium treatment. Total and reduced glutathione levels were higher in primary leaves of uranium (≤ 100 µM U) exposed plants than in control plants. When exposed to 1000 µM U, level of total and reduced glutathione dropped. These results indicate that uranium can cause oxidative stress and cellular redox imbalance. Root DNA integrity was hampered at the highest external uranium concentration. For Phaseolus vulgaris the uranium toxicity threshold is ex-pected to be between 100 µM and 1000 µM U.