Indian traditional medicinal plant Piper attenuatum (Buch-Ham) has been investigated for its antiproliferative activity. Dried powder of fruits of Piper attenuatum (Buch-Ham) was subjected to maceration to prepare various extracts using different solvents in the order of increasing polarity. In vitro antiproliferative activity of all the extract was carried out using MTT assay against MDA-MB-231(Breast cancer) cell line. The Chloroform and Methanol extracts were found to be the most active fractions. The results from MTT assay of isolated compounds from Chloroform extract, NP7C was found to be the most potent antiproliferative agent with IC50 value of 3.83 ?M which is comparable to etoposide 2.37 ?M. Compound NP7L also exhibit significant antiproliferative activity (IC50 of 6.44 ?M) which was comparable to colchicine (IC50 = 6.3 ?M). Thus, the present study indicated that isolated compounds of Piper attenuatum (Buch-Ham) possess great potential to be developed as anticancer agent in future.