This study aimed to evaluate the genotoxic effect of untreated wastewater discharged from the “Kosova A” Thermal Power Plant on the meristematic root cells of Tradescantia pallida, after 72 hours of exposure. In this research, the sample used was polluted water released from the power plant, and seven dilution ratios were prepared (1:1 to 1:7). Distilled water was used as a negative control. The assessment was based on three indicators: the mitotic index, the number of aberrant cells, and the distribution of cells across the mitotic phases. For each treatment, 2000 cells were stained with aceto-carmine and examined under a light microscope. The results showed a clear decrease in cell division activity in all treated groups compared to the control (p < 0.001). The lowest mitotic index was recorded in the 1:2 group (MI = 3.05 ± 0.6%), while the control group showed a much higher value (MI = 16.3 ± 1.1%). Chromosomal damage also increased significantly. The highest number of aberrant cells was observed in the 1:3 group, with 54 ± 3.9 cells, compared to only 9 ± 1.5 in the control. Changes were also seen in the distribution of cells in the mitotic phases. The number of cells in metaphase and anaphase decreased especially in treatments with higher concentrations. For example, in the 1:1 group, only 12 ± 2.5 cells were found in metaphase, compared to 27 ± 3.5 in the control group (p < 0.001). These results suggest that water pollution can seriously interfere with normal cell division and damage the plant’s genetic material. After 72 hours of exposure, analysis of the mitotic index and chromosomal aberrations proved to be a sensitive and reliable method for detecting genotoxic stress under real environmental conditions.