This paper aims to evaluate the cytotoxic effect of ethanolic extract of Abrus precatorius leaves on the murinmastocytoma cancer cell line (P815), and chromatographic study of aqueous extract as well. The Aqueous extract was obtained by decoction and ethanolic was obtained by maceration. The chromatographic study was carried out on a thin layer and on a chromatographic column. The cytotoxicity was sought by determining the percentage of lysis of cancer cells and the inhibitory concentration 50% (IC50) by the MTT assay. Chromatographic analysis in thin layer with increasing of solvent polarity (Hexane / acetate of ethyl) showed the different spots depending on solvent polarity. The column chromatography allowed separating two fractions. A dose dependent cytotoxic effect of the extract was observed on the cancer cell line (P815). It was observed that the ethanolic extract has the best cytotoxic effect with an IC50 of 43.94 μg/mL different from aqueous extract which has a weak cytotoxic effect with an IC50 of 200 μg/mL against 2.5 μg/mL for methotrexate. Ours results suggest that A. precatorius leaves contains several chemical groups and possess a potential anticancer effect in vitro against P815 tumor cell line.