Sesbania Grandiflora (Family: Leguminosae) is a medicinal plant used as tumor suppressant agent in Ayurveda, a traditional system of medicine practiced in sub-continental India. The aim of the study was to systematically investigate and reveal the cytotoxic potential of sesbania grandiflora bark extract [petroleum ether (BP), Chloroform (BC), Methanol extract (BM) and Aqueous extract (BA)] against Brine shrimp lethality bioassay, Allium cepa root model and MTT- bioassay. We tested time and dose dependent specific cytotoxic activity of BP, BC, BM and BA on Artemia salina by brine shrimp lethality assay. The extracts were also investigated with Allum cepa root model for cytotoxic and antimitotic effect. Finally BM and BA were investigated for their cytotoxic potential using PA-1 cell lines containing human ovary epithelial teratocarcinoma cells in vitro. In Brine shrimp lethality bioassay methanolic bark extract of the plant (BM) was found to be most potent with LC50 values of 924.34. In Allium cepa model BM showed maximum growth retarding effect at 10mg/ml with significance of (p<0.01). Finally in MTTbioassay BM was found to be active at 0.001-0.01μg/ml. Methanolic bark extract of sesbania grandiflora contains potent cytotoxic compounds with specific activity against human ovary epithelial teratocarcinoma cells. Further studies are needed to confirm the in-vivo anticancer activity and subsequent isolation and chemical characterization of the active molecules.