The study was conducted to evaluate the anticancer potential of Rhododendron leaf extract and to identify the best possible lead from the reported chemical constituents of Rhododendron. Rhododendron arboreum leaves were collected and dried in a solar dryer for 7 days and were extracted with different solvents. The extracts were evaluated qualitatively and quantitatively to identify and quantify the active components. Biological evaluations such as MTT-based anti-proliferative Assay and activity against reactive oxygen species were conducted for the extracts. A tubulin assay and a cell cycle assay were performed to prove the biological activity of quercetin, which was found to have the highest affinity toward the colchicine binding site of tubulin. As per the overall result of quantitative and anti-proliferative activity, chloroform extracts portrayed excellent anti-proliferative activity (IC50 3.28 µg/ml). CRA exhibited the most potential ROS elevation in the MCF-7 cell line. Molecular docking suggested that quercetin was also found to have the highest affinity towards the colchicine binding site of tubulin (G - 12.08 Kcal/mol). The tubulin assay showed comparable inhibition of microtubule assembly by quercetin compared to paclitaxel. Further, quercetin was also found to inhibit the progression of the cell cycle beyond the G2/M phase in cell cycle analysis. These findings suggest that the CRA of rhododendron species has potential chemical constituents with anticancer potential, and they may be explored further for their effect as anticancer agents.