The phytochemical investigation of Persicaria salicifolia Brouss. ex Willd herb resulted in isolation of trans phytol, β-sitosterol, β-sitosterol-3-O--D-glucoside, luteolin, quercetin, quercitrin, hyperoside and rutin. The compounds were isolated using different chromatographic techniques. The isolated compounds were identified using different spectroscopic techniques including UV, IR, MS, 1 HNMR and 13 CNMR.The antitumor effect of total ethanolic extract of Persicaria salicifolia herb against solid Ehrlich carcinoma (SEC) was examined and the results revealed that the extract has strong antitumor activity. In vitro cytotoxic assay against human breast carcinoma (MCF-7) and prostate carcinoma (PC3) cell lines was carried out using different fractions of alcoholic extract. Methylene chloride and ethyl acetate fractions exhibited the highest activity against breast carcinoma, while petroleum ether extract exhibited the highest activity against prostate carcinoma cell line. Phytol, luteolin and quercitrin were isolated for the first time from Persicaria salicifolia Brouss. ex Willd.