Nerium oleander L. is the widest spread ornamental plant; it is cultivated every where in Egypt as well as in the whole world. We noticed that snails living very close to the plant do not approach it. A chloroformic cardenolide extract was isolated from the leaves of the plant after removing the other constituents with lead acetate; the isolated extract was tested for its molluscicidal activity against the harmful land snails, Theba pisana (Muller) and Eobania vermiculata. The extract was highly active against T pisana with LD₅₀ value of 12.039 µg / gm of body weight, while E vermiculata was less sensitive to the extract, with LD₅₀ value of more than 100 µg / gm of body weight. The results indicate that N oleander is a good source of natural molluscicidal extracts, or compounds which are more toxic to T pisana snails than the present used synthetic pesticides, methomyl and methiocarb.