Treatment of breast cancer is not easy because of the complexity in molecular physiology. Surgery, chemotherapy and radiation therapy includes different sources of treating breast cancer. The systemic chemotherapy faces lot of challenges, mainly adverse effects. So, there is a need of newer drugs to be developed against breast cancer. The present work tries to justify the folklore claims of Tabernaemontana divaricata (L.) R. Br. ex Roem. & Schult. through a sound scientific background using modern analytical tools. It was found that phytoconstituents of the plant showed good docking score against 3ERT protein. The petroleum ether extract and chloroform extract showed anticancer activity. Petroleum ether extract was found to have GI₅₀ value of 18.7µg/ml. Phytochemical Studies lead to the isolation of two compounds, 1 and 2. These compounds, isolated from the leaves were studied and characterized tentatively with the help of modern analytical tools like FTIR, ¹H NMR and MS. Based upon spectral studies, compound 1 was characterized as 2-(1,6a,6b,9,9,12a,14b-heptamethyl 1, 2, 4a, 5, 6, 6a, 6b, 7, 9, 10, 11, 12, 12a, 12b, 13, 14b-hexadecahydropicen-3-yl) propan-2-yl nonanoate. Compound 2 was found to be not pure enough to be characterized. The isolated compounds were also tested for their anti-proliferative activity against breast cancer.