Atrazine, a non-persistent pesticide, belongs to a triazine herbicide group of pesticides and is derived from the s-triazine structure – a six member heterocyclic with symmetrically located nitrogen atoms that are substituted at the 2, 4, 6 – positions. This book describes the physical and chemical properties, toxicity, herbicide action and need for routine monitoring. Also discussed herein is an overview of sensors (with special emphasis on electrochemical sensors) for pesticides in general and atrazine in particular. The concept of molecular imprinting science and technology (MIS&T) is introduced with reference to pesticide monitoring.