Thiabendazole is a fungicide and parasiticide used primarily to control mold, blight, and other fungally caused diseases in fruits and vegetables. It is able to control roundworms, hookworms, and other helminth species which attack wild animals, livestock and humans.

Thiabendazole is applied to some bananas, including Chiquita brand bananas 'to ensure freshness'.

Thiabendazole is also a chelating agent, which means that it is used medicinally to bind metals in cases of metal poisoning, such as lead poisoning, mercury poisoning or antimony poisoning.