For isolation of active components of Azolla pinnata, different extracts were obtained using petroleum ether, chloroform and water. The molluscicidal effect of each extract was examined separately on both healthy and infected Biomphlaria alexandrina snails. The different extracts exhibited significant molluscicidal activities. After twenty four hours, aqueous fraction showed activity (LC₁₀₀ ) at concentration of 500 ppm while the petroleum ether fraction demonstrated activity (LC₁₀₀) at 100 ppm, put the chloroformic naction showed LC₇₅ at concentration of 80 ppm after 24 hrs. Further fractionation of the active chloroformic part on silica gel column chromatography yielded an active eluate with LC₉₀ at concentration of 30 ppm after 24 hr. Also, most extracts showed more Killing effect on the infected snails than the noninfected ones. It could be concluded that fractionation of A. pinnata leads to production of more active molluscicide at lower concentrations.