A series of 5‐arylidene derivatives 3a‐k, as potential antifungal agents, were synthesized in good to high yields by the reaction of 2‐benzimidazolylimino‐4‐thiazolidinone and corresponding aromatic aldehyde in a buffered medium. These compounds were evaluated for their antifungal activities against four agricultural fungi, Botrytis elliptica, Fusarium graminearum, Phytophthora nicotianae, and Rhizoctonia solani. Thereby, it was found that the compound 1 exhibits an antifungal effect against P. nicotianae and B. elliptica, comparable with carbendazim as a standard antifungal. Our results may provide some guidance for development of some novel benzimidazole‐based antifungal lead structures. J. Heterocyclic Chem., 2010.