New benzimidazoles substituted at the 1-position with carbonyl substituents and at the 2-position with a 4-thiazolyl group are effective fungicides and anthelmintics. The compounds as well as processes for their preparation are described along with antifungal and anthelmintic compositions for their use. The 1-position substituent is a hydrocarbon group of from 5 to 12 carbon atoms connected to the carbonyl group through an oxygen or a sulfur atom. The compounds are generally prepared by contacting a 1-unsubstituted benzimidazole with a hydrocarbon radical substituted chloroformate or chlorothiol formate.