One of the leading global causes of environmental contamination, heavy metals hurt agriculture and human health through the food chain. Through the use of mitotic index (MI), chromosomal aberrations (CAs), and DNA damage, the cytotoxic and genotoxic effects of Cr (VI) on the root tips of Allium cepa and Nigella sativa were assessed. Six Cr(VI) concentrations of 50,100,400,700,1000,and 2000 ppm were administered for 6,12,18,and 24 hours. The germination percentages of A. cepa and N. sativa seeds decreased at 400 ppm for both plants, with no germination detected in N. sativa L after 700 ppm application. The percentage of mitotic index in the treated group was significantly lower than that of the control cells after exposure to varying concentrations of Cr (VI) for varying amounts of time. It was determined that these decreases were statistically significant. The reduction of MI in N. sativa root tips was more pronounced than that of A. cepa. The largest abnormal percentages were identified in N. sativa after 24 hours of exposure to 100 ppm, while A. cepa showed abnormal percentages after 24 hours of exposure to 400 ppm. In all mitotic phases, distinct anomalies in the division of root tip cells were found in both plant species. A few examples of these deviations are stickiness, c-mitosis, anaphase-telophase bridges, disturbed laggards, and micronucleus. The comet test, which looks for single-strand breaks in DNA, was used to figure out how dangerous Cr (VI) is to the DNA in A. cepa root cells.