The research aims are to characterize this anthelmintic activity and to isolate the main nematocidal agent of Balanties aegyptiaca plant. The anthelmintic activity was evaluated in vitro by means of an original anthelmintic assay using Caenorhabditis elegans as a biological model. Fluorescence microscopy was used for the determination of the percentage of worms death. The structure elucidation was based on NMR, mass spectroscopic analysis and chemical methods. A bioassay-directed fractionation of the aqueous extract of Balanites aegyptiaca led to the isolation of balanitin-7 (also named diosgenin 3β-O-β-D-xylopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside), as being the principal nematicidal agent. These data indicate that balanitin-7 has an appreciable nematocidal activity, which is not mediated by inducing an anti-acetylcholinesterase activity.