An overview is given of the significance of the imidazole scaffold in crop protection chemistry. The main herbicidally, fungicidally and insecticidally active imidazole classes are presented, together with their synthesis routes, modes of action and biological efficacies. Also, partially and fully saturated imidazole derivatives, such as imidazolines and imidazolidines, oxygenated derivatives, such as imidazolinones and hydantoins as well as annulated derivatives, such as benzimidazoles, are covered. In addition, also the role of imidazoles as intermediates or reagents in the synthesis of other agrochemicals is reported. CONTENTS 1. Introduction 2. Herbicidally active imidazole derivatives 2.1. Acetohydroxyacid synthase inhibitors 2.2. Protoporphyrinogen-IX-oxidase inhibitors 2.3. Miscellaneous modes of action 2.4. Natural products 3. Fungicidally active imidazole derivatives 3.1. C14-demethylase inhibitors 3.2. Tubulin polymerization inhibitors and promoters 3.3. Miscellaneous modes of action 3.4. Natural products 4. Insecticidally active imidazole derivatives 4.1. Nicotinic acetylcholine receptor agonists 4.2. Miscellaneous modes of action 4.3. Natural products 5. Imidazoles as reagents and intermediates in the synthesis of non-imidazole agrochemicals 6. Conclusion