This investigation was aimed at determination of anthelmintic activity of different fractions of Azadirachta indica seeds prepared from the crude aqueous methanol extracts. For this purpose, eggs and adult Haemonchus contortus were exposed to aqueous, ethyl acetate, chloroform and petroleum spirit fractions of A. indica seeds employing standard bioassays. All the fractions of A. indica seeds exhibited dose and/or time dependent ovicidal and wormicidal effects against H. contortus. The best ovicidal activity was demonstrated by the ethyl acetate fraction with LC₅₀= 21.32 µg/ml; whereas, it was 6-14 times lower for the other fractions. Likewise, ethyl acetate fraction @ 50 mg mL^-1 exhibited the best wormicidal effects by killing 83% adult H. contortus one hour post-exposure. Therefore, studies aimed at identification of active anthelmintic principles of A. indica may be focused on ethyl acetate fractions of the plant.

Key words: Anthelmintic, Fractionation, Haemonchus contortus, Neem, Plant extract