Methanolic extracts of different parts of five medicinal plants, Ferula assafoetidaL. resin, Grewia asiaticaL. leaves, Ipomoea hederaceaJacq. seeds, Lepidium sativumL. seeds and Terminalia chebulaRetz. fruits were tested in vitrofor their cytotoxic, phytotoxic, insecticidal, nematicidal and anthelmintic activities. Ipomoea hederaceashowed very significant phytotoxic and cytotoxic activity, with 100% inhibition of Lemna minorgrowth and 100% death of Artemia salinaat concentrations of 1000 and 100 µg mL-1. Grewia asiaticaexhibited very weak activities while Lepidium sativumand Ferula assafoetidashowed moderate to good potential in all three bioassays. The results suggest screening of Ipomoea hederaceaseeds further for isolation of bioactive compounds that may be responsible for its toxic potential.