To investigate the cytotoxic effect of some Bangladeshi medicinal plant extracts, 16 Bangladeshi medicinal plants were successively extracted withn-hexane, dichloromethane, methanol and water. The methanolic and aqueous extracts were screened for cytotoxic activity against healthy mouse fibroblasts (NIH3T3) and three human cancer-cell lines (gastric: AGS; colon: HT-29; and breast: MDA-MB-435S) using the MTT assay. Two methanolic extracts (Hygrophila auriculataandHibiscus tiliaceous) and one aqueous extract (Limnophila indica) showed no toxicity against healthy mouse fibroblasts, but selective cytotoxicity against breast cancer cells (IC501.1–1.6 mg mL−1). Seven methanolic extracts fromL. indica,Clerodendron inerme,Cynometra ramiflora,Xylocarpus moluccensis,Argemone mexicana,Ammannia bacciferaandAcrostichum aureumand four aqueous extracts fromHygrophila auriculata,Bruguiera gymnorrhiza,X. moluccensisandAegiceras corniculatumshowed low toxicity (IC50> 2.5 mg mL−1) against mouse fibroblasts but selective cytotoxicity (IC500.2–2.3 mg mL−1) against different cancer cell lines. The methanolic extract ofBlumea lacerashowed the highest cytotoxicity (IC500.01–0.08 mg mL−1) against all tested cell lines among all extracts tested in this study. For some of the plants their traditional use as anticancer treatments correlates with the cytotoxic results, whereas for others so far unknown cytotoxic activities were identified.