The present invention relates to parasitic helminth PLA2 proteins; to parasitic helminth PLA2 nucleic acid molecules, including those that encode such proteins; to antibodies raised against such proteins; and to compounds that inhibit parasitic helminth phospholipase A.sub.2 activity. The present invention also includes methods to obtain such proteins, nucleic acid molecules, antibodies, and inhibitors. Also included in the present invention are therapeutic compositions comprising such proteins, nucleic acid molecules, antibodies, and/or inhibitors as well as the use of such therapeutic compositions to protect animals from diseases caused by parasitic helminths.