Anthraquinones are described which are antihelminthic and in particular, are useful in compositions for inhibiting Schistosoma sp. in vitro or in vivo. The preferred anthraquinones have the formula: ##STR00001## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each hydrogen, hydroxy, halogen, alkyl, substituted alkyl, alkene, substituted alkene, alkyne, aryl, substituted aryl, cyclic, substituted cyclic, acid group, carbohydrate, or combination thereof, R is a group containing 1 to 12 carbons such as methyl, alkyl, substituted alkyl, aldehyde, hydroxy, hydroxymethyl, acid group, carbohydrate, or combination thereof, and the halogen is I, F, Br, or Cl.